Merge branch 'develop' of github.com:matrix-org/synapse into registration-api-changes in preparation for re-merge to develop.

Define a CLOS-like 'around' modifier as a decorator, to neaten up the 'orig_*' noise of wrapping the setUp()/tearDown() methods

Allow a TestCase to set a 'loglevel' attribute, which overrides the logging level while that testcase runs

Have all unit tests import from our own subclass of trial's unittest TestCase; set up logging in ONE PLACE ONLY

Conflicts:
	webclient/room/room-controller.js

Send multiple candidates at once instead of all individually. Changes spec to include multiple candidates in a candidate(s) message.

Fix bug where we relied on the current_state_events being updated when we are handling type specific persistence

Fix bug where we incorrectly removed a remote host from the list of hosts in a room when any user from that host left that room even if they weren't the last user from that host in that room