better DDS fallback


git-svn-id: svn://svn.tuxfamily.org/svnroot/tesseract/main@1841 b412e182-2ed4-4078-95c4-27dc59f57fa9
don't parse nocompress for compressed textures


git-svn-id: svn://svn.tuxfamily.org/svnroot/tesseract/main@1842 b412e182-2ed4-4078-95c4-27dc59f57fa9
scale textures for dds fallback


git-svn-id: svn://svn.tuxfamily.org/svnroot/tesseract/main@1843 b412e182-2ed4-4078-95c4-27dc59f57fa9