Reformat all files with the new version.

Signed-off-by: Marcus Hoffmann <bubu@bubu1.eu>

Part of #9744

Removes all redundant `# -*- coding: utf-8 -*-` lines from files, as python 3 automatically reads source code as utf-8 now.

`Signed-off-by: Jonathan de Jong <jonathan@automatia.nl&gt;`>

We call `_update_stream_positions_table_txn` a lot, which is an UPSERT
that can conflict in `REPEATABLE READ` isolation level. Instead of doing
a transaction consisting of a single query we may as well run it outside
of a transaction.

We call `_update_stream_positions_table_txn` a lot, which is an UPSERT
that can conflict in `REPEATABLE READ` isolation level. Instead of doing
a transaction consisting of a single query we may as well run it outside
of a transaction.

... instead of duplicating `config.signing_key[0]` everywhere

This encapsulates config for a given database and is the way to get new
connections.

Fix the test to pass the right number of args to the Store constructors

This prevents unnecessary construction of lists

setup_test_homeserver function in utils.

This should fix the bug where the edges of the graph get returned in a
different order than they were inserted in, and so no get_event no
longer returned the exact same JSON as was inserted. This meant that
signature checks failed.

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

fix the copyright holder from matrix.org to OpenMarket Ltd, as matrix.org hasn't been incorporated in time for launch.