Sort the Room's inital state and timeline events before attempting to process them

It turns out that the Session and/or the database were giving us our initial state events in reverse chronological order. This caused us to start with incorrect state until we paginated or otherwise loaded recent events from the timeline. The fix is to sort the events into the correct order before we apply them to the Room state.

Closes #31 (closed)

Maybe also #28 (closed) but we will have to verify that...