UTF-8: Multiple improvements (and detection of possible issue)

UTF-8: Multiple improvements (and detection of possible issue)

This commit started out intending to fix "digit" definition on unicode,
which it mostly does, but a lot more happened in the end, namely:

 * digits apparently are not part of CLDR definition.  I added a section
   in the manual portion of UTF-8 source file that defines digit classes
   for generated sections.
 * Add numbers classification for entire UTF-8.  Currently DragonFly and
   all BSDs do not support "number" type.  However, localedef understands
   it (its supported on Illumos), but currently the number flag value is
   zero, so it's a no-op.  A short term goal is to have DragonFly be the
   first BSD with proper number ctype handling.
 * Redefine "special" ctype once and for all.  There is no definitive
   agreement on what "special" characters are.  According to wiki which
   got it from unicode, it starts with 33 characters (0x20 - 0x2F, 0x3A -
   0x40, 0x5B - 0x60, 0x7B - 0x7E).  However, localedef objects to <space>
   because it sets "graph" and "print" flags, and <space> can't be graph.
   As a result, the <space> is not considered "special" here.  Moreover,
   the punctuation in Latin-1 supplement is "special".  The division and
   multiplication signs are ambiguous, so I set them to special (since
   plus and minus signs are special).  Finally, with the most doubt, the
   punctuation of "general punctuation" block is also considered special
   although I couldn't find convincing evidence either way.  Given the
   lack of definition, I don't think "special" classification is really
   used, especially not in unicode.
 * Fix NON-BREAK_SPACE classification (set as graph and space on previous
   commit)
 * the MICRO character was also warning due to being classified as both
   lower (in Greek section) and punctuation, so remove the punct. class.
 * When possible, don't define graph if digit is defined, and similarly
   with graph and punct.  Both digit and punct also set graph flag so
   having both is redundant.
 * add several new block definitions:
   - Syloti Nagri
   - Common Indic Number Forms
   - Phags-pa
   - Saurashra
   - Kayah Li
   - Rejang
   - Javanese
   - Cham
   - Tal Viet
   - Meetei Mayek & extension
 * Detection of possible bug in localedef
   The Tai Tham definition are producing the wrong code but there's
   nothing wrong with the definitions.  The 6 unused characters between
   the two digit definitions should not be graphable, but as soon as
   one "digit" is defined after the first digit range is defined, all
   the characters between are marked as graphable and digits.  There
   are similar "fill-ins" but so far only with Thai Tam.  It was
   detected while outputting all "digit" types against a python program
   that does the same and this error was reveal.  It requires further
   investigation about exactly what is causing it (and thus where the
   bug is) but right now it's either a bad definition elsewhere that
   affects Thai Tam or localedef has a bug somewhere (avl lookup?)