Remove one-time database cleaning code

Killed processes can still be restored, so this cleaning code could
delete the content we need to view. We'll have to come up with other
way to keep the database clean.
Issue #207: include add subreddit icon if room

Remove the new post icon on the small screen browser activity to make
room for the add subreddit icon which is more relevant to the listview
of subreddits. Add a flag to disable the debug menu so we can see how
the menus will look like on non-debug builds.
Issue #205: add ability to horizontally drag views

Add the ability to touch and drag views sideways. This code merges some
fixes gleamed from Roman Nurik's swipable views gist. Specically, I
couldn't figure out to send the cancel event to disable items from
highlighting and long press from activating. I also added some code to
use the Y movement to decide whether or not to activate swiping. Anyhow,
this code doesn't dismiss anything yet. That will be addressed in a bevy
of other changes...

Also set the chosen state on views when clicking on them. Somehow
calling the ListView#onTouchEvent in the touch listener causes the views
to refresh too early and miss the drawable state change.