Add and use cached batched storage.get_state function.

Federation for end-to-end key requests.

Simplify LoginHander and AuthHandler

Add a few strategic new lines to break up the on_query_client_keys and on_claim_client_keys methods in federation_server.py

Dictionary and list caches

Add some metrics about the reactor

Update to Twisted-15.2.1.

enable registration in the demo servers

Conflicts:
	synapse/http/matrixfederationclient.py