mGerrit: Provide a truely dynamic changelog

+ Add basic support for viewing review.cyanogenmod.org
   (though support is severly crippled till they upgrade to
   Gerrit v2.7)
+ Better handling of swiped away projects/authors
+ Added basic AOKP ROM nightly downloads support

Patch Set 2: Better icons (stolen from android.R.drawable)
           : Better error handling
           : Verbage in strings
           : fix Changelog layout to fully use screen
           : Work around Gerrit v2.6 lackluster APIs
           : Disable DiffViewer in production code
             (still troubled by context:# syntax
             not being respected, AOKP instance
             refuses to provide a return from the
             DiffApi)
Patch Set 3: fix off by one bug in counter

Change-Id: Ifef9b392db429e73210f9b3a37dd1df0e5171641