changes include: fixes lots of possible crashes in several module
loaders and in mmcmp depacker with malformed files. fixes possible
endless loop in the IT loader with malformed files.
git-svn-id: svn://svn.code.sf.net/p/quakespasm/code/trunk/quakespasm@1395 af15c1b1-3010-417e-b628-4374ebc0bcbd