class variables for _settingsSaved, _settingsFailed to easily change all error messages when saving
From shypike:This is the (kind of weird) priority table: TOP_PRIORITY = 2 HIGH_PRIORITY = 1 NORMAL_PRIORITY = 0 LOW_PRIORITY = -1 DEFAULT_PRIORITY = -100 PAUSED_PRIORITY = -2 -100 won't do a thing, since it means: whatever is default.
Split out settings model to support validation.