Adding EventTimeline in preparation for tracking event history.
Added IDs to existing streams.

Last-Event-ID header is confirmed to pass on EventSource reconnect.
Last ID handling for channel subscription.
Adding FileStore collection to client-side JS.
Decreasing reliance on event feed for tree updates.
Using reset rather than fetch on page load.
Refreshing to get new files/folders - less likely to go wrong.
Upgrading to FontAwesome 3.2.0
Performing catch up on first request.
WIP: Replacing comet with polling JSON.
Adding outofdate event to trigger client refresh of stale data.
Merge branch 'ie8-improvements'