Mirror mode support for the Kinect driver

[tomoto]

Here is the patch for the mirror mode support for the Kinect driver. I used #22 as the reference (my kudos to KHeresy).

• Color, Depth, and IR streams with any available pixel formats are supported.
• Sorry for rewriting a lot, but I thought it was necessary to eliminate too many copy-and-pasted frame copy loops. I applied template a lot to achieve this without impacting on the performance. It might look a little cumbersome or overusing at the first glance, but I believe it will contribute to the future maintainability.
• I tested every combination of {Color, Depth, IR} x {all available pixel formats} x {mirror on/off} x {cropping on/off} x {image registration on/off (Depth stream only)} through NIViewer, and all looked fine.
• I also quickly checked the performance around the Depth stream and did not notice any regression. (It even felt a bit faster, but I do not know why.)
• A couple of minor bugs (e,g, wrong calculation of dataSize of Depth stream when both image registration and cropping were on) are also fixed.

[tomoto]

Sorry for another commit after sending the pull request. It is to refactor around KinectStreamImpl and DepthKinectStream to achieve better encapsulation of Windows & NUI dependent details within KinectStreamImpl.