Converted Kiosk mode button back to Options button

In addition added volume control functionality to options menu.
Re-Added a kiosk Button, Added Implementation to Toggle between Tap and Tilt

The Kiosk Button is now a small button in the top left corner of the
main menu.
Removed Difficulty Toggle from the Options screen after talking to Raf
Merge pull request #19 from christoph2005/Alex-Branch

Alex branch