changed diagnostic from "warning" to "note" in the python wrapper generator, to suppress some noise in opencv utilities

work on #2100: pyopencv_to functions now can receive argument information through ArgInfo structure. Non-contiguous input numpy arrays are copied. In case of non-contiguous output array the TypeError is thrown.

Added gabor_threads.py sample

adjust the header parser to support "public virtual" construction and make a tweak for multiple inheritance, fix potential memory problem with Python's IplImage.tostring() method (ticket #1486)

partially wrapped features2d framework
added feature_homography.py sample

fixed "import cv" in the new python samples. corrected Python bindings to match the documentation and vice versa (NOTE: in cv2.stereoCalibrate the parameter ordering has been changed)

upgraded to FLANN 1.6. Added miniflann interface, which is now used in the rest of OpenCV. Added Python bindings for FLANN.

make type registration ordering in cv2.so consistent with the declaration order (fixes the class hierarchy; see ticket #1113)

- static class member modifier processing is fixed (moved from 'rettype' to 'func_modlist')

moved Python bindings source code into src subdirectory; preparing to add python/doc and python/test subdirectories

fixed the ordering of parameters in PyArg_ParseTupleAndKeywords, added correct Ptr<CvDTreeSplit>::delete_obj() (ticket #406)

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