Move the presence handler out of the Handlers object

Spell "domain" correctly

s/domian/domain/g

Try importing at the root level rather than conditionally importing, as per comment

Make synctl read a cache factor from config file

add a url_preview_ip_range_whitelist config param

Always set the config key with an empty list, even if a list isn't specified.
This means that the codepaths are the same for both the empty list and
for a missing key. Since the behaviour is the same for both cases this
makes the code somewhat easier to reason about.

Make email notifs work on the pusher synapse

Add a slaved datastore for account data

Allow receipts for events we haven't seen in the db

Create user with expiry

Fixup add_pusher

Delete old pushers

Use tree cache for get_linearized_receipts_for_room

Remove unused indices

 - Add unittests for client, api and handler

Signed-off-by: Negar Fazeli <negar.fazeli@ericsson.com>

This includes removing both unused indices and indices that are subsets
of other indices.