* Doc bugfix

The documentation page StereoBinaryBM and StereoBinarySGBM says that it returns a disparity that is scaled multiplied by 16. This scaling must be undone before calling reprojectImageTo3D, otherwise the results are wrong. The function reprojectImageTo3D() could do this scaling internally, maybe, but at least the documentation must explain that this has to be done.

* calib3d: update reprojectImageTo3D documentation

* calib3d: add StereoBM/StereoSGBM into notes list