quicksettings tune-up

PS1: move to generic static observer in quicksettings model
PS2: some privatized things and cleanup

PSto-do: get observes for sound and torch only when those tiles are present

-Vanir

Change-Id: I4f2f0321b63992c857b36b6ae1c05c737b195844
Merge "quicksettings tune-up" into jb43