[PATCH] Update Unicode mapping tables to current versions

[PATCH] Update Unicode mapping tables to current versions

The primary motivation for this is to resolve a licensing issue with
these files (the files have been relicensed with a Debian-approved
license), but there were a few minor fixes/additions since the previous
update.  The generation code/scripts required some modernization to get
it working on a current system, as well as needing to handle the format
of CP866.TXT, which is a bit different than the other files.

Gbp-Pq: Name update-unicode-mapping-tables.patch