Fix save to Read Later

It all started with save to Read Later throwing exception with following message: "You need to use a Theme.AppCompat theme (or descendant) with this activity".
It appears that you can't use `android:style/Theme.NoDisplay` on Activities extending android.support.v7.app.ActionBarActivity.
So I have started doing some refactoring and came to conclusion that `SaveReadLaterBookmark` does not need to extend `FragmentBaseActivity`.