This converts calls like super(Foo, self) -> super().

Generated with:

    sed -i "" -Ee 's/super\([^\(]+\)/super()/g' **/*.py

Now that the server supports streaming back JSON responses, it would be nice to
show the response as it is streamed, in the test tool.

* py3 fixes for federation_client
* .well-known support for federation_client

This appears to have stopped working since matrix.org moved to cloudflare. The
Host header should match the name of the server, not whatever is in the SRV
record.

so that you don't necessarily need a config file.

Make it read the config file, primarily.