Front-end proxy: pass through auth header

Support /keys/upload on /r0 as well as /unstable

Fix logcontext leaks in httpclient

Add logging and fix log contexts for publicRooms

Fix error when running synapse with no logfile

So that access-token-in-an-auth-header works.

(So that we can stop riot relying on it in /unstable)

`preserve_context_over_fn` is borked

Sometimes we need to pass headers into these methods

Fixes 'UnboundLocalError: local variable 'sighup' referenced before assignment'

register some /unstable endpoints in /r0 as well

Code_style updates

Fix port script

We changed _simple_update_one_txn to use _simple_update_txn but didn't
yank it out in the port script.

Fixes #2565

Correctly wire in update group profile over federation

PEP8 fixes

E741 says "do not use variables named ‘l’, ‘O’, or ‘I’".

what could possibly go wrong

Fix a logcontext leak in the media repo

Updates to ID checking