Added sound effects on item selection or button click
1. Added two more buttons to the MainActivity:
	a) "Contact Us" button which broadcasts an intent to an email app
	   allowing the user to easily send an email
	b) "About Us" button which opens an AlertDialog with some info

2. Android's Calendar Provider API crashed a HTC One S running Android
4.0.2 although it worked on an emulator running the same version of
Android. As a result, the application now uses the same method of
broadcasting an intent to the Calendar as with pre-ICS versions of
Android (which unfortunately isn't considered best practice).