Split highgui module to videoio and highgui

Tracking-Learning-Detection and MedianFlow

Fix include of imgcodecs

fix compiling reg module after separating imgcodecs from highgui

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.

added samples to use retina in its basic form and for HDR tone mapping

More abstract tracker declaration

This contribution changes the way how trackers should be implemented by
programmer. It should be noted first, that from the user prospective,
Tracker::create() method still can be called with the same effect.
However, there's no more thing as a "constructor" for Tracker, they
should be created via static functions, e.g.
    static Ptr<TrackerMIL> createTracker(const TrackerMIL::Params &parameters=TrackerMIL::Params());

From the programmer's perspective now for every tracker what is declared
in tracker.hpp header is more a "interface", while the real
implementation class can (and has to) be implemented in .cpp file.

Changes in documentation are also included.

ADAS: training app, stumps and waldboost