Background page conversations were trying to trigger events on the inbox
list view which had been destroyed, resulting in a background page
console error of "can't read innerHeight of null".
Avoid this by removing listeners when the inbox window is closed.
When a new message arrives, if its conversation is not already opened,
the background page opens it. If it is alrady open the window is
focused. Finally, the 'message' event is triggered, resulting in
1. the inbox refetches conversations
2. all conversations fetch new messages
TODO: only send this event to the target window
Don't auto open the last conversation. It doesn't make sense now that we
no longer have two column layout.
Don't trigger/listen for selected events. There's no need since the list
item opens a new popup now.
This change removes the timestamp field from messages and conversations
in favor of multiple semantically named timestamp fields: sent_at,
received_at on messages; active_at on conversations. This requires/lets
us rethink and improve our indexing scheme thusly:
The inbox index on conversations will order entries by the
conversation.active_at property, which should only appear on
conversations destined for the inbox.
The receipt index will use the message.sent_at property, for effecient
lookup of outgoing messages by timestamp, for use in processing delivery
receipts.
The group index on conversation.members is multi-entry, meaning that
looking up any phone number in this index will efficiently yield all
groups the number belongs to.
The conversation index lets us scan messages in a single conversation,
in the order they were received (or the reverse order). It is a compound
index on [conversationId, received_at].
Register the runtime callback at the top level view rather than having
each conversation view register independently.
Also refactors Layout into InboxView.
