header only library for CUDA programming

rewritten several functions from calib3d: findhomography, findfundamentalmat, findessentialmat, estimateaffine3d, computecorrespondepilines, convert points{to/from}homogeneous to C++.

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.

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.