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.
bomb commit of gstreamer videocapture and videowriter
Highgui tests for GUI disabled for WinRT;
Warnings fix;
exploring possible bug in optimize_linear_svm
eliminated warnings
add hack to disable optimization of linear svms; improved precision of optimize_linear_svm; add the relevant test, which however requires some big database (so it's disabled by default)
converter stereo correspondence algorithms to the new style
fixed buffer size and restored the use of compressed files in ml's load_save tests.
fixed nonfree compilation with gpu (perf tests)
updated license header in whole gpu module
Merge pull request #687 from vpisarev:fast_lin_svm2
fixed http://code.opencv.org/issues/2899
removed extra whitespaces
Merge pull request #683 from jet47:gpu-license
Merge pull request #688 from jet47:fix-nonfree-compilation
Merge pull request #691 from vpisarev:fix_2899
Fix ant/Java detection in cmake scripts

Mac OS X 10.7 and newer don't come with Java installed. They do
include some stub binaries, which ask the user if they want to
install Java when run.

OpenCV's cmake script just checks for the existence of an ant
binary and assumes that Java's available if ant is. As a result,
cmake will configure the build to use Java and it will fail once
it tries to compile the Java bindings.

This fixes the issue by checking for the exit status of
`ant -version` - it exits 0 if Java is installed, or 1
otherwise.
Add cv::String class