Remove v4.support.Fragment and use native fragments.
Merge pull request #1488 from wordpress-mobile/issue/1436-use-native-fragments

Remove v4.support.Fragment and use native fragments.
Merge branch 'develop' of https://github.com/wordpress-mobile/WordPress-Android into issue/1336-reader-swipe-posts

Conflicts:
	src/org/wordpress/android/ui/reader/ReaderActivity.java
	src/org/wordpress/android/ui/reader/ReaderSubsActivity.java
	src/org/wordpress/android/ui/reader/ReaderTagFragment.java