Add rate limiting for sync service downloading

A background sync operation can make the system unusable as every single network operation will basically never finish until the SyncAdapter is done downloading.
Fix crash when resuming activity after staying on Downloads tab
Fix PlaylistAdapter not picking up deleted cache after first pass
Only show notification after entire playlist sync is done
Bump release version
Lint fixes
#142 Add pull to refresh to all views
Remove refresh button from everywhere
Remove pointless intermediate messages
Remove huge backlog of change logs
Merge branch 'RateL' of https://github.com/daneren2005/Subsonic
Merge branch 'PullRefresh' of https://github.com/daneren2005/Subsonic
Fix color bar being under server message
Accidental commit, revert
Fix pull to refresh triggering on any scroll up
Make SelectArtistFragment inherit from SelectListFragment
Preview images for widget
german: polish