Revert "Merge pull request #1776 from wordpress-mobile/issue/remove-helpshift-from-3.1"

This reverts commit f8c9238e246b1d334488e087940256403cfafb52, reversing
changes made to 365e1b27231629a54da12fb8620e1897b1140483.

Conflicts:
	WordPress/src/main/java/org/wordpress/android/GCMIntentService.java
	WordPress/src/main/java/org/wordpress/android/WordPress.java
use helpshift 3.5.0
fix auto tag for login screen
split the unreadable blog list strings into separate entries
Merge pull request #1814 from wordpress-mobile/issue/1811-helpshift-reintegration

fix #1811 helpshift reintegration and small fixes