Returning to Win2k value is possible via this CMake option:

    cmake -DOPENCV_EXTRA_FLAGS="/D_WIN32_WINNT=0x0500" ...

by this new function we can set libjpeg "scale_denom" parameter and load jpeg images scaled 1/2 - 1/4 - 1/8
other image formats resized after loading

Also move cv::linemod to own header

e.g. <opencv2/core/core.hpp> become <opencv2/core.hpp>

Also renamed <opencv2/core/opengl_interop.hpp> to <opencv2/core/opengl.hpp>