Fixed bugs with blob's width/height; bounding-box using Contour

* The bounding box can be calculate directly from the Contour,
without the necessity of fitting polygons before.
Removal unused incanter; more intuitive name of func; func blob size
Fixing misunderstanding of the clusters-to-binary func
Removal of unnecessary func; func to get an image's clusters
Functions to get internal and external points of a Contour
More generic funcs using Points; removal of redundant funcs
Tests of cluster functions
More complex test image
Func to invert the pixels' value of bw image