Integrated our motion tracking and homography

* Homography function is now non-looping and instead returns the 4
points of a polygon that define the bounding box
* Motion detection function now returns a rectangle defining a bounding
box
* Both of the above functions execute serially and then draw their boxes
later, so as not to interfere with each other
* Added example source video 'source3.mp4'
* Added example target object 'makeup.png'