heh... Microsoft's implementation of snprintf doesn't conform to the standard!

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@11139 387891d4-d844-0410-90c0-e4c51a9137d3
additional string safety

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@11140 387891d4-d844-0410-90c0-e4c51a9137d3