Added the defaultNorm() method to the DescriptorExtractor class. This method returns the default norm type for each descriptor type. The tests and C/C++ samples were updated to get the norm type directly from the DescriptorExtractor inherited classes.

This was reported in feature report #2182 (http://code.opencv.org/issues/2182). It will make it possible to get the norm type usually applied matching method for each descriptor, instead of passing it manually.

This should allow many algorithms to take advantage of more parallelization
technologies.

Made all STL usages explicit to be able automatically find all usages of
particular class or function.

changed default parameters of SURF, which improved its performance. Restored bi-linear interpolation in SURF descriptor extractor. Added test for SURF homography + check for non-zero (positive) responses.

(see also r8895, r8887 and #2043)

added dedicated <modname>_init.cpp files with initModule_<modname>() functions and all the relevant structures; made BackgroundSubtractorMOG/MOG2 derivatives from Algorithm; cleaned up MOG2 implementation and made it multi-threaded.

added initModule_features2d(). Possibly solved problem when the linker excludes seemingly unused detectors/descriptors.

#1349 tbb::mutex is moved to outer scope to be sure that its initialization is completed before the parallel loop

lot's of changes; nonfree & photo modules added; SIFT & SURF -> nonfree module; Inpainting -> photo; refactored features2d (ORB is still failing tests), optimized brute-force matcher and made it non-template.

Small change in the SURF algorithm to be sure that without TBB the template parallel_for is not used
(the reason: the parallelization in the SURF algorithm conflicts with ThreadingFramework, which is a temporary substitute of TBB for ARMs)

replaced alloca() (a.k.a. cvStackAlloc) with AutoBuffer or vector() everywhere. cvStackAlloc() is still defined, but we do not need alloca() anymore to compile and run OpenCV (fixes #889 and may be some others)