LIB-467 Inbox event handling

[marc-scig]

We want to

• implicitly refresh messages on foreground
• avoid refreshing messages every time the inbox is displayed, unless we're loading a newly retrieved - message in response to an incoming push
• display the loading spinner until the we're sure that the message index is up to date and the cursor has finished loading
• make sure the loading spinner status is maintained on rotation, if messages are still being refreshed

[marc-scig]

The isProcess check in onCreate has been removed. It's not that great of an idea in the long run, since there's no firm guarantee that the process name will actually match the package name. We also don't stand to benefit from it here, and it could actually do more harm than good with respect to keeping the RichPush class hierarchy in sync across processes.

[caseycrites]

:shipit:

[jtowle]

:ship: