Log Message:
mupdf: Update to 1.16.0

pkgsrc changes:
 - (re)add curl option to build mupdf with curl support (disabled by default).
   Unlike previous versions that supported curl now mupdf with curl support is
   installed as a separate binary as `mupdf-curl' as done by upstream.

Changes:
1.16.0
------
api: Major overhaul of color management architecture.
api: Improved functions to verify/sign PDF documents.
api: Number tree accessor function pdf_lookup_number.
api: Parse and handle more options for PWG output.
api: Removed obsolete gproof document type.
api: User callbacks for warning and error messages.

epub: Changed default page size to A5.
epub: Draw embedded SVG documents in EPUB/XHTML.
epub: New Noto fonts covering more unicode scripts.
epub: Support small-caps font-variant.
pdf: Add Redact annotation type and function to apply redactions.
pdf: Add/remove/change encryption and password when saving PDF files.
pdf: Improvements to text handling in PDF filter processor.
pdf: MP and DP operators now call begin/end_layer device methods.
pdf: New and improved progressive loading.
svg: Draw external images in SVG documents.

mutool show: Add 'form' selector to list PDF form fields.
mutool sign: Sign PDF documents from the command line.
mutool sign: Verify signatures in PDF documents from the command line.
viewer: Option to save a script of user actions for replay with mutool run.
viewer: Runtime toggle for ICC and spot rendering.
viewer: Tooltip when hovering over a link in mupdf-gl.