Added missing break statement to notification button code in DeviceViewController
Added "Switch map to day mode" menu item to DeviceViewController storyboard
Removed dupe viewDidDisappear: implementation from ScannerViewController, unsubscribe from NSNotificationCenter in dealloc
Moved subscription to DBUpdatedNotification to more appropriate viewDidLoad
Implemented a method to discover if ScannerViewController is selected and topmost
In ScannerViewController DBUpdatedNotification handler, only refreshProfile when isSelectedAndTopmost
Defined IGMapDayMode NSString *const
Implemented "Switch map to day mode" button handler in DeviceViewController
Oops, fixed conditional refreshProfile in ScannerViewController
Don't add translucent black layer in XMOverlayView when in day mode. It's too slow for iPhone 4
Merge pull request #140 from TheStalwart/daymode

Day mode for map. It's considerably faster on iPhone 4