Erik Johnston d9aa645f86 Reduce size of joined_user cache
The _get_joined_users_from_context cache stores a mapping from user_id
to avatar_url and display_name. Instead of storing those in a dict,
store them in a namedtuple as that uses much less memory.

We also try converting the string to ascii to further reduce the size.
2017-04-25 14:38:51 +01:00
..
2016-01-07 04:26:29 +00:00
2016-08-12 15:31:44 +01:00
2017-04-25 14:38:51 +01:00