Shift Button Update

I've begun work on my 'shift' button. I've figured out how to make one
button shift. I've tried hooking up all four button to the shift
command in the XIB file, but this caused some weird glitches; some
buttons would shift when certain buttons were pressed, but never all of
them. For my next commit I want to figure out how to make all buttons
shift when the 'shift' button is pressed and edit the sound files. Some
were too long and some too short.