Eliminate the concept of 'Recipients' (plural). There is now just
a 'Recipient', which contains an Address that is either an individual
or a group ID.
MMS groups now exist as part of the group database, just like push
groups.
// FREEBIE
This was a holdover from Signal's origins as a pure SMS app.
It causes problems, depends on undefined device specific behavior,
and should no longer be necessary now that we have all the
information we need to E164 all numbers.
// FREEBIE
This adds android auto support accordign to
https://developer.android.com/training/auto/messaging/index.html#messaging
However, since android auto is not officially supported in my country,
the functionality is limited. Which means that I have not been able
to fully test everything yet.
What work is:
* Message notification is shown.
* When you click on it, the message is read.
Closes#5880
