combinations of translation, rotation, and uniform scaling equals four degrees of freedom

Added 2 inline functions in persistence.hpp
So that the '>>' operator works correctly for std::Vector<KeyPoint> and
std::Vector<DMatch>

- Allows using non-default device names such as /dev/v4l/by-path/pci-0000:00:1d.0-usb-0:1.1:1.0-video-index0

CvVideoWriter_GStreamer assumes a JPEG encoded stream if the height of
the given frame size is 1.

Added a writeFormat() method to Algorithm which must be called by the
write() method of derived classes.

syntax of cmake "get_filename_component" changed after version 2.8.11

for cmake version < 2.8.11
  get_filename_component(<VAR> <FileName> PATH [CACHE])

for cmake version >= 2.8.11
  get_filename_component(<VAR> <FileName> DIRECTORY [CACHE])

Update OpenCVConfig.cmake

Update OpenCVConfig.cmake.in

1. Following condition is True on each iteration becuase -1 % 0xFF is 255 not -1

code = cv2.waitKey(100) % 0x100
if code != -1:
   break

this were resetting point position on each cycle not on key press as intended

2. Previous small bug were masking serious bug with matrix operation on matrices of incorrect size.
   As the result on 2nd iteration of internal cycle program has crushed.

   I have fixed it too, matrix operation was taken from examples/cpp/kalman.cpp where it looks like
   randn( processNoise, Scalar(0), Scalar::all(sqrt(KF.processNoiseCov.at<float>(0, 0))));
   which is something totally different from previous code here.

   Example behave as it should now, i.e. point moving by circle trajectory as in C++ example.