-Add R_CopySubimage to copy portions of one texture into another.
-Add V_LoadConsoleFont to create an array of Textures from the CONCHARS lump, for future use in text printing.

git-svn-id: http://odamex.net/svn/root/branches/texmanager@4280 b0bcef46-2027-0410-bd56-ab726e9a1d04