Remove some we don't care about. Set some other ones we do care
about but don't currently adhere to to warn. Set the max warnings
threshold to the current number of warnings, so we don't introduce
more of them. Fix a bunch of legit lint errors and add exceptions
to various places in the test code that does funny things with
'this'.
If we have shared the session with a device which is subsequently blacklisted,
we need to start a new session for the next message.
Rather than doing this proactively (which would be subject to false-positives
and require slightly awkward tracking of who we had shared the session with),
we check the list of who we have shared the session with on each send, and
start a new session if any of them are blocked.
Fixes https://github.com/vector-im/riot-web/issues/2146.
Instead of trying to maintain a list of devices we need to share with, just
check all the devices for all the users on each send.
This should fix https://github.com/vector-im/vector-web/issues/2568, and
generally mean we're less likely to get out of sync.
