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;
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.
Update Android toolchain to the latest version supporting NDK r8e
fixes in bundle adjustment code by Nils Hasler
fix the crash when calling dft
use clflush replaces clfinish
this test is unstable (fails from time to time), let's disable it until fixed
fix for #2806 (missing 'nu03' field of moments)
fixed assert condition (trueRightDisp can be empty)
fixed warnings
fixed nonfree test (run it only on one gpu device)
Merge pull request #730 from vpisarev:ba_fix
Merge pull request #731 from bitwangyaoyao:2.4_fixDft
Merge pull request #732 from apavlenko:disable_unstable_test