Log Message:
Update courier-unicode to 2.3.0

Changes since 2.1:
* Unicode 15 update. Added unicode_derived_<name>() lookup for derived \ 
core properties. Added unicode_general_category_lookup() for general category \ 
lookups. Fix GB11 rule.
* configure.ac: gcc 12, autotool updates.
* Fix compilation error on CentOS 7.
* unicode_bidi.c: Implement unicode_bidi_combining(). Implement canonical and \ 
compatibility decomposition and canonical composition.
* unicode_bidi.c (unicode_bidi_needs_embed): Make its return code what its \ 
documentation says its return code is.
* Implement unicode_bidi_needs_embed(), unicode_bidi_cleaned_size(), \ 
unicode::bidi_override, unicode_bidi_calc and unicode_bidi_calc_levels return a \ 
unicode_bidi_direction object, to indicate whether the computer paragraph \ 
embedding level was explicitly computed or defaulted.
* courier-unicode-version.m4: split version checking macro into its own m4 file.
* unicode::bidi_calc - an empty string with an explicit embedding level should \ 
return the requested embedding level.
* unicode::iconvert::convert, fix uninitialized variable.
* Implement bidirectional algorithm, canonical or equivalent character mappings.
* Unicode 13 update. Adds lookup of EastAsianWidth property, emoji property \ 
lookup, adds an alternative sequence-based grapheme API that handles \ 
multi-character emoji rules.
* Add bidi property lookups.
* Makefile.am: Regenerate docs due to broken man page links.
* unicodebuf.c (unicode_buf_remove): Bug fix.