* removed unnecessary memcpy
* fixed minor memory leak

moved precomp.hpp before all other headers (to repair PCH mechanism). moved tables from the header to datamatrix.cpp

some more minor fixes in datamatrix: warnings eliminated, replaced MMX intrinsics (which are not recommended to use on x64) with SSE2.

Added to objdetect module: meanshift grouping (groupRectangles_meanshift(...) for input rectangles); new pedestrian detection model, trained on the Daimler base (getDaimlerPeopleDetector(...) ).
Some changes in the HOGDescriptor class interface(objdetect.hpp) (added useMeanShiftGrouping parameter to the detectMultiScale(...) function)

a big patch; use special proxy types (Input/OutputArray, Input/OutputArrayOfArrays) for passing in vectors, matrices etc.

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