Port Presence Data Engine to tp-qt4 0.5, and add Services and Properties

Review Request #100968 - Created March 29, 2011 and submitted

Dario Freddi
This patch ports the data engine to Telepathy Qt4 0.5.x, and adds new Service operations for setting avatars and nicknames. It also enhances data retrieval and fixes some small bugs here and there.
Engine explorer works flawlessly
David Edmundson
Dario Freddi
Review request changed
David Edmundson
Ok, ship it on the condition that you address the other comments in another patch.

Also could you post to the ML about your plans for the plasmoid. It seems to be gaining some extra functionality, so it would be good to share your ideas with the group first.