OpenCV at type-independent

[ipa-jcl-cs]

• make .at independent of type and number of channels by creating following methods:
  template void setMatValuePtr(cv::Mat& image, int row, int index, double value);
  void setMatValuePtr(cv::Mat &image, int row, int index, double value);
  template T getMatValuePtr(cv::Mat& image, int row, int index);
  double getMatValuePtr(cv::Mat& image, int row, int index);
• tried to take care about the intendation ;)

[ipa-rmb]

opened directly for integrating into 320: ipa320#93