mGerrit: (WIP) make Stalker mode clearer

Patch Set 2: include simple sharing on main screen
             (layout and messages need work)
Patch Set 3: Move away from buttons to more UI
             friendly actionable imageviews
           : add actionable imageviews to PropretiesCard
           : simplify share message
           : fix stalker mode in at all entry points
           : update volley lib
Patch Set 4: Allow following of a single project by clicking
           : the project's path on CommitCards
Patch Set 5: Add Gravatars to code reviewers ListView
Patch Set 6: introduce a listener to handle boilerplate code
Patch Set 7: Fix onClick Crashes
           : Fix Owner gravatar parsing
           : Make tracking consistent across views

Change-Id: I00eeea9631ca0207e6229524e73cbbf74c6b752e