moved some old stuff to the legacy module; merge "compat_c.h" headers and moved to the legacy as well. moved implementation of many non-critical/obsolete inline functions and methods to .cpp to improve Opencv build time

fixed canny test; fixed mhi-global test & implementation (hopefully, for the last time); added sse 4.1 & 4.2 support (not working in Xcode for some reason); moved splineInterpolation to color.cpp; fixed a few bugs in documentation

extended Python bindings; not merged into cv.cpp yet; and many of the helper functions, like pyopencv_to_*, pyopencv_from_* etc. are still missing

added more helper macros to the function declarations, to assist the Python wrapper generator. Fixed memleak in Mat::operator()(Range,Range) and the related functions (Mat::row, Mat::col etc.)