First merge of new stats into develop

This is a huge chunk of code, it's incomplete, and there are TODOs.

The problem I'm having is I need to break things down into individual achievable issues.  This is the first step.  I had to stop somewhere.

This effectively rewrites how stats are displayed.  Big hairy things remaining:

* Followers & Comments aren't implemented
* Effectively no styling done
* Caching of data & state issues when switching between units/time periods
* General stability of data coming back not crashing the app
* Offline experience