Big change here is now a looping sound displays the glowing ring around
it's images. I also renamed the SoundManager to the XoundManager because,
well, xoundBoard.

Jason: pay some attention to the 'buttonPress' method in XBViewController.
it's a nice little pattern for dealing with groups of buttons etc. If
you don't know what casting is, ask me.

My next step: a Boolean for displaying the title of the button, and
I gotta make all the names in rave drumkit shorter.

What I want from you is a couple soundboards, and some design for the settings
page. I don't want to give up a lot of screen real estate in play mode, thinking access via swipe. Which would be a good time to introduce mr. gesture recognizer.