Start SoundPropertyActivity and code cleanup

When the properties button is pressed it will now open up the property
activity.
Add new strings to res
Add extra variables and functions to Clip class

The clip needs to hold extra variables describing the sound.  I've also
added a play and stop function that will call the syncPlay/syncStop
functions of the clip.
Add play and stop helper functions
Add SoundPropertyActivity for modifying sounds

This is a quick mock-up of the activity to update sound properties.
Populate the songs early in setup