Changing settings to use fragment for main settings

SettingsActivity:
-moved all layout controls other than the service toggle switch to MainSettingsFragment
-Added two FrameLayouts to hold the main settings fragment and (later) the advanced settings fragment

Prefs:
-changed setRingerType() argument from int to RingerType.  This should help avoid bugs where a single-choice dialog selection index is being passed in instead of a RingerType

MainSettingsFragment:
-moved all controls from SettingsActivity here.
-explicit onClick methods have been changed to inline OnClickListeners since the click was being passed back to the SettingsActivity (which should not have to implement methods for the fragments)
-Additional settings not reachable for now.  This needs to be stripped out and placed in a separate fragment, so that SettingsActivity shows both the main settings fragment, and either a link to the AdvancedSettingsActivity, or embeds the advanced settings fragment