Newer/older + auto-advance for one-pane

- Moved MessageOrderManager code from 2-pabe to the base class.
- Most of the code is shared between 1-pane and 2-pane.

- Also fixed the bug where we re-created MessageOrderManager every time
the user taps newer/older, which was the reson the newer/older button
temporarily got disabled when you tapped them.
Before this CL we stopped MOM in uninstallMessageViewFragment, but now that
we don't reuse fragments this means we stops MOM when we remove the current
message view, and re-created a new one when a new message view is created.
Now we stop MOM when the right pane gets hidden (2pane) or when showing
the mailbox/message list (1pane).

- Also removed a now unused callback onMessageShown() from MessageViewFragment.
We used to update MOM on this event, but now we do this in
installMessageViweFramgment().

Bug 4575586

Change-Id: Idc4aba184f318e0c086afc29dcbe42364e2b51b3
17 files changed