#45, #46: Convert images before optical frow processing.
#45, #46: Create return codes enum.
Merge pull request #53 from it-workshop/wp/45/1

#45, #46: Application class. Optical flow processor interface.
#46: Farneback optical flow processor
#46: Enabled FarnebackOpticalFlowProcessor
#46: adding all points, including ones which are out of range
#46: demo flow target