message is now passed as Unicode from C++
Also encode directly from Unicode, elminating the need for kCharSet.

NOTE:  This will not magically allow your font to render all unicode
characters...  The fonts are still limited in what they can display,
so you may not get the characters you expect when typing.  However,
whomever you're chatting with will at least see the same thing you do.
Merge pull request #73 from zrax/fix_unicode_chat

Fix Unicode characters in chat