Log Message:
Update to 1.8.22, as requested by Christian Biere in PR 18460.
Changes:
NEW FEATURES

- Now support many Windows code pages in addition to ISO charsets.
- HTMLDOC now supports heading levels 1 to 15.
- HTMLDOC now allows the author to omit headings from
  the TOC using the _HD_OMIT_TOC attribute.
- HTMLDOC now supports remote book files when running
  from the command-line.
- HTMLDOC now supports hexadecimal character constants (&#xFF)
- New --nup and NUMBER-UP options for PostScript and PDF output.
- HTMLDOC now logs HTML errors.
- HTMLDOC now supports the A3, B, Legal, and Tabloid size names.
- HTMLDOC now supports embedding of the base Type1 fonts
  in PostScript and PDF output.

CHANGES

- HTMLDOC now calculates the resolution of the body
  image using the printable width instead of the page width.
- HTMLDOC should now compile out-of-the-box using the Cygwin tools.
- HTMLDOC no longer inserts whitespace between text inside DIV elements.
- HTMLDOC now supports quoted usernames and passwords in URLs.
- HTMLDOC now defaults unknown colors to white for background colors and
  black for foreground colors. This should make documents that use
  non-standard color names still appear readable.
- The HTML parser now allows BODY to auto-close HEAD and visa-versa.

BUG FIXES

- HTMLDOC could crash when checking if a URL is already cached.
- HTMLDOC didn't adjust the top margin when changing the
  page header if the comment didn't appear at the top of a page.
- HTMLDOC didn't initialize the right number of TOC headings.
- When using a logo image in the header, the header was
  placed too low on the page.
- "make install" didn't work in the fonts directory.
- "€" didn't work, while "€" did: the
  character name table was not sorted properly...
- Links didn't always point to the right page in PDF output.
- XRX comment output could crash HTMLDOC.
- Fixed-width columns in tables could be resized by HTMLDOC.
- When writing PostScript commands, some printers reset
  their duplexing state when a new setpagedevice command
  is received; we now cache the current duplex state and
  change it only as needed.
- The MEDIA SIZE comment didn't adjust the printable
  size for the current landscape setting.
- HTMLDOC placed the header one line too high.
- When continuing a chapter onto the next page, H3 and
  higher headings would be indented the wrong amount.
- HTMLDOC wouldn't compile using GCC under HP-UX due to
  a badly "fixed" system header file (vmtypes.h).
- Generating a book without a table-of-contents would
  produce a bad PDF file.
- The Xerox XRX comments used the wrong units for the
  media size, points instead of millimeters.
- IMG elements with links that use the ALIGN attribute
  didn't get the links.
- Header and footer comments would interfere with the
  top and bottom margin settings.
- Fixed a bug in the htmlReadFile() function which
  caused user-provided title pages not to be displayed
  in PS or PDF output.
- The table-of-contents would inherit the last media
  settings in the document, but use the initial settings
  when formatting.