rename two additional classes that got missed

git-svn-id: https://android.svn.wordpress.org/trunk@961 a6565c4b-a94d-4d28-bb26-aa9e5ab542c0
Adding an mShouldFinish boolean to WPActionBarActivity so that we can track which activities should finish after a new activity is started from the Menu Drawer. Fixes #428

Also added an experimental new flat WP icon for the ActionBar. I think I like it.

git-svn-id: https://android.svn.wordpress.org/trunk@962 a6565c4b-a94d-4d28-bb26-aa9e5ab542c0