v0.4.2

• core
  • Added cv::mean binding with single argument
  • fix the write-strings warning
  • return temp pointer fix
• examples
  • add counter example
  • add motion-detect command
  • correct counter
  • remove redundant cast and other small cleanup
  • set motion detect example to fullscreen
  • use MOG2 for continous motion detection, instead of simplistic first frame only
• highgui
  • ability to better control the fullscreen window
• imgproc
  • add BorderType param type for GaussianBlur
  • add BoundingRect() function
  • add ContourArea() function
  • add FindContours() function along with associated data types
  • add Laplacian and Scharr functions
  • add Moments() function
  • add Threshold function
• pvl
  • add needed lib for linker missing in README
• test
  • slightly more permissive version test
• videoio
  • Add image compression flags for gocv.IMWrite
  • Fixed possible looping out of compression parameters length
  • Make dedicated function to run cv::imwrite with compression parameters