prefs: only show variable highlighting prefs in the global prefs dialog
http://bugs.activestate.com/show_bug.cgi?id=99818

(integrated from komodo (trunk) change 80923 by marky)

git-svn-id: https://svn.openkomodo.com/repos/openkomodo/trunk@13256 b87d16e7-d29f-4ee1-b5ec-817d645d335f