Show rendering errors in a dialog
Submitted by Jeff F.T.
Assigned to Jeff F.T.
When there is a hang/traceback/error while rendering, what usually happens is that pitivi just sits there and the user is not notified that there is a problem; only running pitivi in a terminal reveals the problem.
We should catch exceptions and whatnot and have a dialog that at least tells the user that something went wrong, and maybe display the errors in a scrollable widget so they can be copy-pasted/saved somewhere for debugging.
Imported from https://bugzilla.gnome.org/show_bug.cgi?id=635874