Tracking-Learning-Detection and MedianFlow

This contribution includes the following logical components into
tracking module:

*) Change Rect to Rect2d into headers for Tracker's methods;
This contribution includes the following logical components into
tracking module:

*) Change Rect to Rect2d into headers for Tracker's methods;
*) MedianFlow tracker;
*) extensible benchmark to compare trackers interactively and
assess
them quantitatively;
*) TLD tracker (work-in-progress);

Work was funded by Google Summer of Code 2014 initiative. Mentors:
Gary
Bradski and Vadim Pisarevsky.
@vpisarev Vadim, this standardPatch is pushed inside the model on every iteration of the loop. Now, what it makes internally is it pushed it into std::vector. If I'll allocate standardPatch outside, memory reallocation won't happen and on each iteration we'll push the copy of the same patch, ie. all members of std::vector will refer to the same memory.