V11 Google Auth and ui updates

This is a bit mess as it includes both some UI hacking I was doing, along with all the new code for Google Account authentication.

Specifically the app will now show your on device configured google accounts as options for account type choice, and get the necessary OAuth2 keys etc to use it.

It also sets the XMPP SASL providers appropriately to use it, based on a key in the password string.

https://dev.guardianproject.info/issues/346