message: highgui(win32): improve waitKey() timeout condition
  use cv::getTickCount() instead of Win32 GetTickCount()
  process message queue before timeout exit
diff: @@ -1965,7 +1965,8 @@ static void showSaveDialog(CvWindow* window)
  CV_IMPL int
  cvWaitKey( int delay )
  {
  - int time0 = GetTickCount();
  + int64 time0 = cv::getTickCount();
  + int64 timeEnd = time0 + (int64)(delay * 0.001f * cv::getTickFrequency());
  for(;;)
  {
  @@ -1973,13 +1974,13 @@ cvWaitKey( int delay )
  MSG message;
  int is_processed = 0;
  - if( (delay > 0 && abs((int)(GetTickCount() - time0)) >= delay) || hg_windows == 0 )
  - return -1;
  -
  if( delay <= 0 )
  GetMessage(&message, 0, 0, 0);
  else if( PeekMessage(&message, 0, 0, 0, PM_REMOVE) == FALSE )
  {
  + int64 t = cv::getTickCount();
  + if (t - timeEnd >= 0)
  + return -1; // no messages and no more time
  Sleep(1);
  continue;
  }
  