Use WPTextView and switch to Open Sans in other widgets used in stats.
Use WPTextView (and Open Sans) in the bar chart Tooltip item.
Use Open Sans in the bar graph.
Merge branch 'develop' of https://github.com/wordpress-mobile/WordPress-Android into 1669-Stats-open-sans

Conflicts:
	WordPress/src/main/res/layout-sw600dp/stats_visitors_and_views_fragment.xml
Missed one file when switched to all TextViews to WPTextView
Another TextView that I missed in the previous commits
Updating Mixpanel to 4.3.0.

Updating to latest version of Mixpanel as they patched it to allow us
to get access to super properties which will allow us to properly
track them.
Fixed bug where we were wiping out all of our super properties.
Use TypefaceCache rather than loading new typeface. props @nbradbury
Merge pull request #1769 from wordpress-mobile/issue/fix-broken-superproperties

Issue/fix broken superproperties
Use view.getContext rather of getActivity that could be null.
Merge pull request #1768 from wordpress-mobile/issue/1669-Stats-open-sans

Use Open Sans in Stats
cherry picked 65beeb114c392d6c931ef928ef939130bdfaca20
add ABTestingUtils
Merge pull request #1770 from wordpress-mobile/issue/helpshift-workaround

helpshift workaround
remove the _contact us_ button from preferences (it's already in Help and Support)
Merge pull request #1771 from wordpress-mobile/issue/double-contact-us-button

remove the _contact us_ button from preferences (it's already in Help and Support)
3.1-rc-1 version bump
use new utils version
fix a merge conflict in zbetagroup