Add isDeviceMotionEnabled & isPanGestureEnabled

[junpluse]

Summary

Provides options to disable device motions and pan gestures in PanoramaView.

Detail

Add following new properties to PanoramaView:

// PanoramaView.swift

public var isDeviceMotionEnabled: Bool { get set }

public var isPanGestureEnabled: Bool { get set }

Also make PanoramaPanGestureManager public to allow detailed settings of pan gesture.

// PanoramaView.swift

public lazy var panGestureManager: PanoramaPanGestureManager { get set }