If all deferreds wait a reactor tick before resolving then there is
always a chance to add an errback to the deferred so that stacktraces
get reported, rather than being discarded.

Split out the schema preparation and update logic into its own module

SH CAS Required Attribute

Split the sections of EventStreamHandler.get_stream that handle presence

Fix some races in the synapse presence handler caused by not yielding…

Allow optional config params for a required attribute and it's value, if specified any CAS user must have the given attribute and the value must equal

Provide ability to login using CAS

into separate functions.

This makes the code a bit easier to read, and means that we can reuse
the logic when implementing the v2 sync API.

Add a flag to initial sync to include we want rooms that the user has left

Allow synapse's useragent to be customized

Remove log line that was generated whenever an error was created.

Remove log line that was generated whenever an error was created. We are now creating error objects that aren't raised so it's probably a bit too confusing to keep