SlimActions: add new actions and cleanup

A bit cleanup.

As well add 4 actions:

- camera intent
- play/pause music
- next music track
- prev music track
- wake up device

As well check for system ready on the other audio actions which are already present.

ToDo: One of the rare classes which are very bad documented. We need to add code comments
ASAP

Change-Id: I987b1a719f34a40358bc733b9b1b00d0bc36a823
Merge "SlimActions: add new actions and cleanup" into kitkat3