A generic approach to delay writing of some prefs on SN. Define a list
of prefs which shouldn't be written immediately, as changes often happen
in bursts.
Merge branch 'public/7.7' into hotfix/ss-buffered-prefs
Buffer some more prefs updates on SN.
New icons for Slacker & WiMP
Merge branch 'public/7.7' into public/7.8