request and check for camera access

camera.cs

			var status = AVCaptureDevice.GetAuthorizationStatus (AVMediaType.Video);

			if (status == AVAuthorizationStatus.Authorized) {
				//yay
			} else if (status == AVAuthorizationStatus.NotDetermined) {
				AVCaptureDevice.RequestAccessForMediaType (AVMediaType.Video, (bool accessGranted) => {
					if (accessGranted) {
						//yay
					} else {
						//boo
					}
				});
			} else {
				//boo
			}