Add a cache for get_push rules for user, fix cache invalidation

backfill fixes

Make joining #matrix:matrix.org over federation quicker

Enable changing the interface the metrics listener binds to

Improve presence performance in loadtest

Make the appservice use 'users_in_room' rather than get_room_members …

Erikj/txn logging fix

Merge branch 'markjh/pusher_performance_master' of github.com:matrix-org/synapse into hotfixes-v0.9.0-r5