The function git_wcwidth() returns for a given unicode code point the
width on the display:
-1 for control characters,
0 for combining or other non-visible code points
1 for e.g. ASCII
2 for double-width code points.
This table had been originally been extracted for one Unicode
version, probably 3.2.
We now use two tables these days, one for zero-width and another for
double-width. Make it easier to update these tables to a later
version of Unicode by factoring out the table from utf8.c into
unicode_width.h and add the script update_unicode.sh to update the
table based on the latest Unicode specification files.
Thanks to Peter Krefting <peter@softwolves.pp.se> and Kevin Bracey
<kevin@bracey.fi> for helping with their Unicode knowledge.
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
