Use main thread event loop for navigator event processing

Use main thread event loop for navigator event processing

Removes the need for an extra thread by creating the event handler's
socket notifier in the context of the main thread.

Change-Id: If8c7bb986074083b5b9a7b9c96734a970ba32f92
Reviewed-by: Sean Harmer <sh@theharmers.co.uk>
Reviewed-by: Robin Burchell <robin+qt@viroteck.net>