Philip Withnall authored Mar 04, 2014 and Olivier Crête committed Apr 28, 2014

The GSource created by g_pollable_output_stream_create_source() on a
NiceOutputStream would never have been dispatched, due to not having any
poll events (or anything else); it only works for TCP streams because of
a GCancellable child source which is triggered by the TCP code.

Fix that by making ComponentSource suitable for G_IO_IN and G_IO_OUT
again, and adding that as a child source for UDP output stream GSources.