Add typedefs for the standard OpenCV native types.

This commit adds typedefs for the standard types that are used by OpenCV.

The purpose of these type defs is to match the types used on matrix operations i.e. CV_8UC1 to simplify notation and help to avoid errors.

This allows programmers to specify:
cv::Mat m(cv::Size(100, 100), CV_8UC1);
m.at<CvType8UC1>(y, x);

// rather then
// Is this signed or unsigned (correct or wrong)? Implementation defined...
m.at<char>(y, x); 

Conversion can be managed as followed if needed (between native and soft types):
int type = cv::DataType<CvType8UC1>::type;

Happy to change the name structure of the typedef's if there is a structure that better matches your style guide, please let me know.