Rounds all WPNetworkImageViews with `AVATAR` type.

Rounds gravatars in Comments, Notifications and the Reader.
Added border around noticon to match design.

Circularization of avatars is now processed in an AsyncTask tom improve performance.
Should have used `executeOnExecutor()` for the circularize bitmap task.

Props @nbradbury
upgrade to android-gradle 0.14.0
fix test manifest of wpcomrest to work with android-gradle 0.14.0
Merge branch 'hotfix/3.3.1' into release/3.4

Updated to support Android Studio 0.9
Merge branch 'release/3.4' into develop

Updated to support Android Studio 0.9
Added `SITE_AVATAR` enum to keep blavatars square.
Merge branch 'develop' into issue/1958-round-avatars
Merge pull request #1970 from wordpress-mobile/issue/1958-round-avatars

Avatar Circularization
Merge branch 'develop' into issue/1880-widow-words