zip tga fix


git-svn-id: http://svn.code.sf.net/p/sauerbraten/code@4993 07af1644-1164-4067-b897-63bf4dc9b748
IMG_LoadTyped_RW workaround


git-svn-id: http://svn.code.sf.net/p/sauerbraten/code@4994 07af1644-1164-4067-b897-63bf4dc9b748