introducing a tutorial for the retina model
adding retina tutorial
updated tutorial, need spell check, validation, nicer images and a discussion on parameters
updated tutorial, rapid spell check, retina parameters discussion added
added retina code tutorial
updated first image sample
minor update
minor updates for doc redirections and tutorial images size
Initial Windows RT support commit.
GPU module turned off;
TIFF support turned off;
Windows Managment and Video IO (VFW) turned off.
Multiple Windows RT fixes

TIFF build was fixed;
Direct Show back-end was enabled;
More accurate guards implemented.
More accurate guards for WinRT features in CMake.
Highgui tests for GUI disabled for WinRT;
Warnings fix;
Multiple fixes for WinRT

Fixed flann build with NEON;
Fixed Haming distance with NEON;
Honest cvRound for WinRT added;
cvRound test added;
Video IO with direct show disabled;
use perf test replace performance sample
Video IO tests turned off for ARM WinRT.
HAVE_WIN32UI and HAVE_VFW checks and defines added.
Perf tests for Video IO on WInRT fixed.
fixed bug in TVL1 optical flow:

initial optical flow was not cleaned during the second call
Port dft.py sample from cv to cv2
Fix typo leading to heap corruption in OutputArray::create