Add AirPlay support

Limelight/Database/TemporarySettings.h

@@ -34,6 +34,7 @@
 @property (nonatomic, retain) NSNumber * pointerVelocityModeDivider;
 @property (nonatomic, retain) NSString * uniqueId;
 @property (nonatomic, retain) NSNumber * resolutionSelected;
+@property (nonatomic, retain) NSNumber * externalDisplayMode;
 @property (nonatomic) enum {
     CODEC_PREF_AUTO,
     CODEC_PREF_H264,