Update to use new timeout function everywhere.

The existing deferred timeout helper function (and the one into twisted)
suffer from a bug when a deferred's canceller throws an exception, #3842.

The new helper function doesn't suffer from this problem.

Fix matrixfederationclient.py logging: Destination is a string

Set SNI to the server_name, not whatever was in the SRV record

Bump timeout on get_missing_events request

When we do a join, always try the server we used for the alias lookup first.

Fixes #2418

We want to wait until we have read the response body before we log the request
as complete, otherwise a confusing thing happens where the request appears to
have completed, but we later fail it.

To do this, we factor the salient details of a request out to a separate
object, which can then keep track of the txn_id, so that it can be logged.

Add python_version phone home stat

Fixes #3843

don't ratelimit autojoins

Add variable for changing the max upload size in Docker container

Return a 404 when deleting unknown room alias

Fix more b'abcd' noise in metrics

Fix typo in README, synaspse -> synapse

Signed-off-by: Aaron Raimist <aaron@raim.ist>

Signed-off-by: Aaron Raimist <aaron@raim.ist>

Fix some b'abcd' noise in logs and metrics

Python 3 compatibility: make sure that we decode some byte sequences before we
use them to create log lines and metrics labels.

... to stop things which try to import `types` getting `synapse.types` instead