Log Message:
unifont: update to 15.0.02.

2023-05-20: Release 15.0.02
   * N.B.: This is the last planned version to build TrueType
     font files as part of the standard font build with

           make BUILDFONT=1

     In the future, only OpenType font files will be part of
     the ordinary font building using the hex2otf program.
     TrueType fonts will have to be built manually using

           cd font
           make truetype

   * Minor update to allow for separate building of TrueType
     and OpenType fonts.  This is in preparation for the future
     removal of TrueType font files from default font builds,
     in preference for OpenType font files.  That change is
     planned for the release of Unifont 15.1.01, which will
     correspond to the release of the Unicode 15.1.0 standard
     scheduled for September 2023.
   * Added Doxygen annotation to C programs and corresponding
     ".h" header files.  Annotated output is generated in a
     new "doxygen" subdirectory.  Doxygen output consists of
     a browsable set of HTML pages and a hyperlinked PDF document.
   * Updates to make files to fix issues with redundant building
     under some circumstances.
   * Added 196 Plane 2 and Plane 3 Chinese ideographs drawn by
     湖 远星 to the basic Unifont font files for coverage of
     the General Standard Chinese Characters set.  Also added
     biang glyphs drawn by Ming Fan.
   * Fullwidth CJK characters that appeared to be boldface in
     the range U+FF00..U+FFEF were updated using glyphs from
     Wen Quan Yi, with some modifications.