trivial commit
trivialcommit
trivial: cleaning junk
Contour slicing from cv::Mat functions

OpenCVContourMatcher has a class function and I also included a utility
function, thus far I’ve avoided declaring namespaces but when we figure
out what’s going where in the final product we can simplify that code.
Merge branch 'contourmatching-opencv' of https://github.com/izewiske/3Hat into contourmatching-opencv
Merge branch 'contourmatching-opencv' of https://github.com/izewiske/3Hat into contourmatching-opencv