-Update libtextscreen from Chocolate Doom 2.0.0

git-svn-id: http://odamex.net/svn/root/trunk@4603 b0bcef46-2027-0410-bd56-ab726e9a1d04
-Merge from trunk into sdl20 (again).

git-svn-id: http://odamex.net/svn/root/branches/sdl20@4604 b0bcef46-2027-0410-bd56-ab726e9a1d04