#1145/#1146: These were caused by the programmatic switching of pages.  Some of the other controls (in this  case, the Gtk.TreeView) allow for events to be processed in their own handlers, and causing an expose_event to  be called before Page.switched_to() was invoked.  This is safe, but an assertion was in place to check for pages  being seen when they weren't supposed to.  Since this can happen during a switch, removing this assertion.
#1145/#1146: These were caused by the programmatic switching of pages.  Some of the other controls (in this 
case, the Gtk.TreeView) allow for events to be processed in their own handlers, and causing an expose_event to 
be called before Page.switched_to() was invoked.  This is safe, but an assertion was in place to check for pages 
being seen when they weren't supposed to.  Since this can happen during a switch, removing this assertion.


Sanva/shotwell-gsoc,jof/shotwell,damianmoore/shotwell,polymeris/shotwell,h4ck3rm1k3/shotwell,jimbonator/shotwell,Sanva/shotwell-gsoc,ritchiewilson/shotwell,jof/shotwell,jof/shotwell,ritchiewilson/shotwell,abrauchli/shotwell,h4ck3rm1k3/shotwell,jimbonator/shotwell,abrauchli/shotwell,jimbonator/shotwell,h4ck3rm1k3/shotwell,polymeris/shotwell,damianmoore/shotwell,Sanva/shotwell-gsoc,ritchiewilson/shotwell,polymeris/shotwell,abrauchli/shotwell,damianmoore/shotwell