Call gtk.gdk.threads_init() to inform pygtk that we might be doing calls
from remote threads.
* pitivi/ui/viewer.py:
The fix to the threading issue was in fact to call
gtk.gdk.threads_enter() and _leave() before and after calls to gtk
being made from a non-main thread.


git-svn-id: svn+ssh://svn.gnome.org/svn/pitivi/trunk@766 d3729300-e425-0410-8a4c-d956edccc248