split ToastUtils in ToastUtils+AuthenticationDialogUtils
remove ptr and smooth progress bar dependencies
move broadcast actions from Wordpress.java to PullToRefreshHelper
reimport PullToRefreshHelper from its new location
Merge branch 'develop' into issue/1633-move-ptr-to-utils-subproject

Conflicts:
	WordPress/src/main/java/org/wordpress/android/ui/reader/ReaderPostListFragment.java
	WordPress/src/main/java/org/wordpress/android/ui/stats/StatsActivity.java
	WordPress/src/main/java/org/wordpress/android/util/AuthenticationDialogUtils.java
Merge pull request #1636 from wordpress-mobile/issue/1633-move-ptr-to-utils-subproject

fix #1633 move ptr to utils subproject