-drawcolumn_t and drawspan_t now store const pointers to the texture source and mask.
-R_DrawColumnRange now uses its texture mappers to calculate the texture source rather than using Texture's lookup table.

git-svn-id: http://odamex.net/svn/root/branches/texmanager@4256 b0bcef46-2027-0410-bd56-ab726e9a1d04
-Remove the column lookup tables from Texture.

git-svn-id: http://odamex.net/svn/root/branches/texmanager@4257 b0bcef46-2027-0410-bd56-ab726e9a1d04
-Create a texture mapper for sprites.
-Remove the column array based version of R_DrawColumnRange.

git-svn-id: http://odamex.net/svn/root/branches/texmanager@4258 b0bcef46-2027-0410-bd56-ab726e9a1d04
-Refactor the patch and wall texture caching code to remove duplication.
-Fix a crash when floor/ceiling textures are not found but are assumed to be sky texture transfers from line number 0xFFFF.

git-svn-id: http://odamex.net/svn/root/branches/texmanager@4259 b0bcef46-2027-0410-bd56-ab726e9a1d04