d'oh - didn't look closely at the propertyNames() API

git-svn-id: svn://svn.icculus.org/fs2open@11064 387891d4-d844-0410-90c0-e4c51a9137d3
fix dumb recursion bug

git-svn-id: svn://svn.icculus.org/fs2open@11065 387891d4-d844-0410-90c0-e4c51a9137d3
this is now unnecessary

git-svn-id: svn://svn.icculus.org/fs2open@11066 387891d4-d844-0410-90c0-e4c51a9137d3
add a file traversal class and use it in two places

git-svn-id: svn://svn.icculus.org/fs2open@11067 387891d4-d844-0410-90c0-e4c51a9137d3
fix a loose end in directory iteration

git-svn-id: svn://svn.icculus.org/fs2open@11068 387891d4-d844-0410-90c0-e4c51a9137d3