Log Message:
Update htmldoc to 1.8.27.
Based on PR 40223.

Pkgsrc changes:
 * Change HOMPAGE for open source version.
 * Add missng dependency on devel/zlib.
 * Optionify of SSL support and let gnutls to selectable.
 * Rename undocumented htmldoc-gui option to x11, it's better match for pkgname.

CHANGES IN HTMLDOC v1.8.27

    BUG FIXES

	- Fixed a crash bug that appeared when more than 10 blank
	  pages were present in a document (PR #6223)
	- Color changes were not reflected in PRE text (STR #129)
	- Remote URLs did not always work on older operating
	  systems (PR #6179)
	- Image filenames using % escapes were not decoded
	  properly.
	- Rows using BGCOLOR that spanned across multiple pages
	  did not render properly (PR #6149)
	- Rows no longer start on a new page due to a cell with
	  both HEIGHT and ROWSPAN specified (PR #6086)
	- CMYK JPEG images caused HTMLDOC to crash (PR #6106)
	- Table cell width calculations didn't always account for
	  the proper minimum width (STR #121)
	- Images were not copied when generating indexed HTML
	  output to a directory (STR #117)
	- Changing the bottom margin resulted in text that was
	  formatted below the bottom margin.
	- The Monospace-Oblique font was not embedded properly in
	  PDF files.

CHANGES IN HTMLDOC v1.8.26

    BUG FIXES

	- Outline and keyword strings in PDF files are now stored
	  as Unicode (STR #113)
	- The Flate compression code could get in an infinite
	  loop if it ran out of memory (STR #101)
	- Book files saved from the GUI did not handle filenames
	  with spaces (STR #105)
	- Fixed and re-enabled the ASCII85Device filter support
	  in PostScript Level 2/3 output (STR #116)
	- Character entities in the first word of a file were not
	  rendered properly (STR #111)
	- Fixed-size table columns were incorrectly resized when
	  a table width was also specified and there was extra
	  space to distribute (PR #6062)
	- Text could "walk" up or down when in-line images were
	  used (PR #6034)
	- Row backgrounds incorrectly replaced cell backgrounds
	  when the first cell in a row used ROWSPAN (PR #6033, PR
	  #6036)
	- HTMLDOC did not correctly parse FONT FACE attributes
	  (PR #6006)
	- Images in Level 2/3 PostScript output did not work on
	  some printers (PR #6000)
	- The GUI did not use the first page header (PR #5978)

CHANGES IN HTMLDOC v1.8.25

    NEW FEATURES

	- Added "--overflow" and "--no-overflow" command-line
	  options to show or hide the content-too-large errors;
	  the default is "--no-overflow".
	- Added "--header1" command-line option and "HEADER1"
	  page comments to set the page header for the first page
	  of each chapter.
	- Added "timing" and "remotebytes" debug data generation.
	- Added DejaVu font collection to better support Cyrillic
	  and Greek text; the new fonts are available under the
	  generic names "monospace", "sans", and "serif".
	- Added "--referer" command-line option and corresponding
	  CGI-mode support to pass Referer: information in HTTP
	  requests (STR #91)

    CHANGES:

	- On Windows, HTMLDOC now logs CGI mode errors to a file
	  called "htmldoc.log" in the Windows temporary
	  directory.
	- HTMLDOC no longer uses Base-85 encoding for image data
	  when producing Level 2 and 3 PostScript output. It
	  appears that many printers and PostScript interpreters
	  cannot properly decode this data when the original
	  image data is not a multiple of 8 bits.
	- HTMLDOC now renders STRONG elements in boldface instead
	  of bold-italic to match the W3C recommendations.
	- HTMLDOC now automatically inserts a TR element before a
	  TD or TH element as needed to improve web site
	  compatibility; this also triggers a HTML error in
	  --strict mode.

    BUG FIXES

	- "$HFIMAGEn" didn't work in a header/footer string.
	- HTMLDOC could crash when rendering a table.
	- Book files were not used in CGI mode (STR #69)
	- Cookies were not sent in HTTP requests (STR #71)
	- Table cells were not aligned properly when the ROWSPAN
	  attribute was set to 1 (STR #73)
	- HTMLDOC crashed when rendering unresolved hyperlinks in
	  aligned images (STR #62)
	- Documented the HTMLDOC_NOCGI environment variable (STR
	  #63)
	- HTMLDOC sometimes crashed when rendering tables with
	  background colors (STR #65)
	- HTMLDOC would crash when writing encrypted strings
	  longer than 1024 bytes (STR #66)
	- HTMLDOC didn't set the data directory when running in
	  CGI mode on Windows.
	- HTMLDOC could crash when loading the Symbol.afm file
	  (STR #93)
	- HTMLDOC did not always honor HEIGHT attributes in table
	  rows.
	- Tables with a mix of colspan and rowspan sometimes
	  caused cells to be moved vertically outside the cell.

CHANGES IN HTMLDOC v1.8.24

    NEW FEATURES

	- HTMLDOC now provides limited cookie support via the
	  "--cookies" command-line option and via the cookies
	  passed by a browser in CGI mode.
	- HTMLDOC now features a CGI mode which provides PDF
	  conversion functionality for web servers.
	- HTMLDOC now generates a document outline for each
	  input file or URL in webpage mode; the outline shows
	  the title for the file and links to the first page
	  containing that file.
	- HTMLDOC now offers an "htmlsep" output type which
	  generates HTML output with a separate file for each
	  heading in the table of contents.
	- HTMLDOC now includes LINK elements in generated HTML
	  so that intelligent browsers like Mozilla can show
	  next/prev/contents/top buttons.
	- HTMLDOC now supports the BORDERCOLOR attribute for
	  tables, a MSIE extension.
	- The "strict HTML" mode now reports unresolved local
	  links.
	- Added support for HP LaserJet 5000 and Xerox DocuPrint
	  2000/100 printer commands.
	- Added multiple header/footer image support.
	- Links to external URLs are now resolved so that the
	  output file can be moved without affecting them.

    CHANGES

	- The command-line now allows --fontsize values from 4
	  to 26 to match the GUI.
	- Now use a 0.001 point tolerance when checking for
	  content that overflows the page/cell.
	- HTMLDOC no longer enables interpolation of 2-color
	  images.
	- The default vertical alignment of images is "BOTTOM"
	  to match the HTML specification.
	- Paragraph spacing is only applied to the first table
	  after a paragraph.
	- The tabloid media size was 10 points too short in
	  length.
	- The table formatter now subtracts the outside border
	  and padding widths for percentage-based widths.  This
	  helps to eliminate "truncation or overlapping" errors.
	- Dropped support for FLTK 1.0.x when building the GUI.
	- The default vertical alignment is now "bottom" inside
	  paragraphs to correctly align different sized text and
	  images to the baseline.
	- Indexed images are now written as PDF image objects
	  when encryption is enabled; this works around a
	  serious bug in Acrobat 6 which tries to decrypt the
	  colormap of in-line images twice, causing some very
	  strange colors!
	- Table captions can now be bottom aligned.
	- Blocks now break at the bottom of a page if the
	  current line height + standard line height goes below
	  the bottom of the page; this prevents images with
	  captions from getting erroneously moved to the top of
	  the next page.
	- Character entities are now supported in HTML
	  attributes and unknown or invalid character entities
	  are left as plain text.
	- Changed handling of NOWRAP for some tables.
	- The --permissions option now supports multiple
	  permission keywords in a single invocation.
	- Dropped support for MacOS 9 and earlier.
	- HTMLDOC now breaks between images that are too large
	  to fit on a single line, to match the behavior of
	  Mozilla/Netscape (STR #7).
	- HTMLDOC now handles XHTML input more cleanly.
	- HTMLDOC no longer specifies an interpolation
	  preference for images in PostScript or PDF output (STR
	  #8)
	- The DT element no longer applies an italic style (PR
	  #5178)
	- HTMLDOC now ignores content inside a STYLE element
	  (PR #5183)

    BUG FIXES

	- Switching between landscape and portrait orientations
	  would cause margin creepage.
	- Images did not default to align=bottom, and the
	  align=bottom line spacing calculation was incorrect.
	- Whitespace before a link was underlined.
	- Fixed a table column sizing bug.
	- HTMLDOC didn't read back the HTTP response properly in
	  all situations.
	- Fixed some more PNG transparency cases.
	- The PageBoundingBox comments in PostScript output did
	  not account for the back page when duplexing was
	  enabled.
	- HTMLDOC generated an incorrect image mask for some
	  images.
	- The first page of each chapter did not use the custom
	  page number if it was placed inside the heading.
	- HTMLDOC did not reset the rendering cache before each
	  page when producing N-up output; this caused font
	  errors in some cases that prevented the document from
	  printing or displaying properly.
	- Eliminated a common cause of "table too wide"
	  formatting errors,
	- Fixed a bug when applying a table background color to
	  a cell without a border that cross a page boundary.
	- Fixed some calls to strcpy with overlapping arguments.
	- The names object was never set when the name objects
	  were written.
	- Character entities were not decoded/encoded inside
	  HTML comments.
	- The current heading was not always correctly
	  substituted when used in the page header or footer.
	- When converting web pages from the GUI, the
	  table-of-contents page number preferences were
	  incorrectly used.
	- PDF page effects/transitions were not put in the right
	  part of the page dictionary, causing them not to be
	  used by the PDF reader application.
	- The _HD_OMIT_TOC attribute was not being honored for
	  HTML output.
	- HTMLDOC now handles "open" messages from the MacOS X
	  Finder (STR #3)
	- The GUI did not load or save the "strict HTML" setting
	  (STR #6)
	- The HTML version of the title page did not set the ALT
	  attribute for the title image (STR #10)
	- The HTML version of the table of contents did not
	  correctly nest the lists in the parent items (STR #10)
	- Borders around left and right-aligned images were not
	  drawn properly (PR #5112)
	- Grayscale PDF output was not truly grayscale (STR #32)
	- Fixed a table-of-contents bug introduced in 1.8.24rc1
	  which caused the PDF document outline and actual TOC
	  pages were not rendered properly (STR #37)
	- Links were not rendered due to a bug that was
	  introduced in 1.8.24rc2 (STR #41)