fix #1367
remove native fragments and use v4.support.Fragment because we're using nested fragments
Merge pull request #1424 from wordpress-mobile/issue/1367-post-upload-npe

fix #1367
Removed the TODO and added a comment regarding the mix usage of android.app.FragmentTransaction and support Fragment.
Merge pull request #1434 from wordpress-mobile/issue/1432-stats-crash-getChildFragmentManager

Fix #1432: remove native fragments and use v4.support.Fragment because we're using nested fragments
2.9-beta-3 version bump.
Merge branch 'develop' of https://github.com/wordpress-mobile/WordPress-Android into issue/1336-reader-swipe-posts