fix: panes: ignore iframe/browser elements that are not Komodo panes
http://bugs.activestate.com/show_bug.cgi?id=101711
r=marky

(integrated from komodo (trunk) change 83466 by toddw)

git-svn-id: http://svn.openkomodo.com/repos/openkomodo/trunk@14135 b87d16e7-d29f-4ee1-b5ec-817d645d335f