Fixes SMS auto-populate issue on KitKat

This should fix the issue #8. If the Android version is KitKat or above, it uses the new way of populating the message body. Otherwise, it uses the old way. This is described here: http://stackoverflow.com/questions/20079047/android-kitkat-4-4-hangouts-cannot-handle-sending-sms-intent

I also edited the SimpleDemo application to include SMS sharing functionality so you can test this out.