Added [MXSession eventsFromToken]
Defined m.presence event type
Added MXEvent.isState
Added events streaming
As streaming is now enabled, make sure [MXData close] is called in the tests
Added a TODO for canceling the pending eventsFromToken request.
In a real life app, it is minor issue.
Fixed tests compilation warnings
Added [MXRoomData registerListener]
Made the testCase parameter in doMXSessionTest* functions optional.
So that we can call these functions twice and more in the same testCase (Useful to test live events)
Tested live events listener