Removing NOTIFICATION_PERFORMED_ACTION from analytics.
remove Helpshift library
remove Helpshift helper
remove helpshift calls
remove Helpshift resources
remove ABTestingUtils, only used for Helpshift
update GCMIntentService comment
Merge pull request #1772 from wordpress-mobile/issue/remove-notification-performed-action-from-analytics

Removing NOTIFICATION_PERFORMED_ACTION from analytics.
Merge pull request #1776 from wordpress-mobile/issue/remove-helpshift-from-3.1

Remove helpshift from 3.1
3.1-rc-2 version bump
Merge branch 'release/3.1' into develop

Conflicts:
	WordPress/src/main/java/org/wordpress/android/GCMIntentService.java