RDB's Unicode patch. Fonts are now used in Unicode mode where

RDB's Unicode patch. Fonts are now used in Unicode mode where
possible and we have a single unified means of trying to display any
Unicode code point. Instead of the various ad-hoc translation modes
we had before, we now have a single `codepage' option which allows
us to treat the incoming (and outgoing) text as any given character
set, and locally we map that to Unicode and back.

git-svn-id: http://svn.tartarus.org/sgt/putty@1110 cda61777-01e9-0310-a592-d414129be87e