Make background black, text size much larger and text colour grey.
Lock screen to portrait mode for now.
Mishmash of changes - improve interface.

 - Now has countdown of time remaining.
 - Remove slow crossfade from green to red, replaced with green-to-black
   flash at start and fade up from black-to-red over last ten seconds of
   timer.
 - Change green-red flash when finished to red-black flash.
 - Change "Restart" to "Time up"
Remove unused includes.
Add space before /> in XML.
Merge pull request #1 from ajps/master

Pull in ajps' changes