-Add optional parameters to StdStringToLower and StdStringToUpper to only use the first n chars of a cstring.
-TextureManager now handles TEXTURE1/2 lumps that have duplicate texture names.

git-svn-id: http://odamex.net/svn/root/branches/texmanager@4465 b0bcef46-2027-0410-bd56-ab726e9a1d04
-Apply the fix from r4466 to the texmanager branch.

git-svn-id: http://odamex.net/svn/root/branches/texmanager@4467 b0bcef46-2027-0410-bd56-ab726e9a1d04