Also discussed previously in #213 (Github Pull Request).

shared-secret-auth and rest-auth logging is still at `INFO`
intentionally, as user login events seem more important to keep.
Those modules typically don't spam as much.

We recently had someone in the support room who set it to `false`
and the playbook ran without any issues.

This currently seems to yield the same result as 'none', but it's
better to avoid such behavior.

Refer to 524436ebef and #230 (Github Issue).

Fixes #230 (Github Issue).

Related to https://github.com/Half-Shot/matrix-appservice-discord/issues/510

It adds support for a new `DISABLE_SENDER_VERIFICATION` environment
variable that can be used to disable verification of sender addresses.

It doesn't matter for us, but we upgrade to keep up with latest.

Related to #223 (Github Pull Request)

Looks like these client ids are actually integers,
but unless we pass them as a string, the bridge would complain with
an error like:

    {"field":"data.auth.clientID","message":"is the wrong type","value":123456789012345678,"type":"string","schemaPath":["properties","auth","properties","clientID"]}

Explicitly-casting to a string should fix the problem.

The Discord bridge should probably be improved to handle both ints and
strings though.

Regression since 174a6fcd1b3, #204 (Github Pull Request),
which only affects new servers.

Old servers which had their passkey.pem file relocated were okay.

ef5e4ad061 intentionally makes us conform to
the logging format suggested by the official Docker image.

Reverting this part, because it's uglier.

This likely should be fixed upstream as well though.

Somewhat related to #213 (Github Pull Request).

We've been moving in the opposite direction for quite a long time.
All services should just leave logging to systemd's journald.

Fixes a regression introduced during the upgrade to
Synapse v1.1.0 (in 2b3865ceea).

Since Synapse v1.1.0 upgraded to Python 3.7
(https://github.com/matrix-org/synapse/pull/5546),
we need to use a different modules directory when mounting
password provider modules.

Fixes a problem introduced by da6edc9cba.

Related to #145 (Github Pull Request).

This is a new feature of Synapse v1.1.0.

Discussed in #145 (Github Pull Request).

Well, `config.yaml` has been playbook-managed for a long time.
It's now extended to match the default sample config of the Discord
bridge.

With this patch, we also make `registration.yaml` playbook-managed,
which leads us to consistency with all other bridges.

Along with that, we introduce `./config` and `./data` separation,
like we do for the other bridges.

I've been thinking of doing before, but haven't.

Now that the Whatsapp bridge does it (since 4797469383),
it makes sense to do it for all other bridges as well.
(Except for the IRC bridge - that one manages most of registration.yaml by itself)

Doesn't matter much, but it makes it consistent with the other bridges.

- following spantaleev transition of the telegram brigde
- adding a validate_config task

appservice-irc doesn't have permission to create files in its project
directory and the intention is to log to the console, anyway. By
commenting out the file names, appservice-irc won't attempt to open the
files.

This means we need to explicitly specify a `media_url` now,
because without it, `url` would be used for building public URLs to
files/images. That doesn't work when `url` is not a public URL.

Regression since 4e8543ce21