Don't loop over all rooms ever in typing.get_new_events_for_user

Add config option to specify where generated files should be dumped

Allow specifying directories as config paths

Allow specifying a directory to host a web client from

Add utility to parse config and print out a key

Usage:

```
$ python -m synapse.config read server_name -c homeserver.yaml
localhost
```

Revert previous commit. Instead, always download matrix-angular-sdk as a requirement, but don't complain (when we do check_requirements) if we don't have it when we start synapse.

Don't make pushers handle presence/typing events

When logging in fetch user by user_id case insensitively, *unless* there are multiple case insensitive matches, in which case require the exact user_id

Clean up some of restructured text formatting in the README.rst

Add generic update instructions to UPGRADE.rst

Add m.room.avatar to default power levels.