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

normal bayes classifier has been parallelized using TBB; letter_recog sample updated to demosntrate knearest & bayes classifiers (thanks to Konstantin Krivakin for the patches)

* if the filename looks like a URI, it is opened in non-blocking mode, cvQueryFrame() could skip frames or grab one frame more than once
* if the filename looks like a filename, it is opened in blocking mode. cvQueryFrame() grabs consecutive frames
* otherwise the filename is interpreted as a gstreamer pipeline as used with gst-launch. The last element of the pipeline has to have the property name=to-opencv

added downsample function into gpu module, refactored it a little bit, added guard for CUDA related include in cascadeclassifier_nvidia_api.cpp