* Move tmk_core/common/backlight to quantum/backlight
* Add guards to backlight inclusion
* Add guards to backlight inclusion
* Update backlight guards on clueboard/60
* Use full paths to avoid vpath issues
* Get audio working on clueboard/60
* add keys for music mode
* Change doubles to floats
* add keys for all the songs
* revert to the default startup sound
* Remove music mode until we can figure out why it crashes