Added options to handle camera mirroring. — Virtual Touch Screen 2 Steam update #2912010

Certain cameras such as the one in the Kinect V2 were found to have strange mirroring behavior. I have added two new configuration options to give more control over the mirroring, allowing more flexibility in general, which in turn makes it possible to fix the mirroring behavior of strange cameras. Camera -> Camera Mirroring This defaults to true for the old behavior, but if toggled will flip the image horizontally. Tracking -> Swap Handedness Defaulted to false for the old behavior, but if toggled it will flip left/right for gesture processing, which is also needed when using a camera with alternate mirroring behavior. (I also want to add that the depth sensing capabilities of the Kinect V2 are not used in Virtual Touch Screen 2-- I only mention it as an example because it is the only camera I have seen so far which exhibits the alternate mirroring configuration.)