SF feature request #77 - more efficient single pass algorithm for ccNcompt

[mohawk2]

https://sourceforge.net/p/pdl/feature-requests/77/

ccNcompt currently uses a 2-pass algorithm, but there is a more efficient single pass algorithm described in "A linear-time component-labeling algorithm using contour tracing technique" (2004):
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.95.6330

And here is an implementation in C: http://www.codeproject.com/Tips/407172/Connected-Component-Labeling-and-Vectorization

There's also pseudocode in the wikipedia article: https://en.wikipedia.org/wiki/Connected-component_labeling#Pseudocode_for_the_one-component-at-a-time_algorithm

Karl adds:

That's fine to add a new one pass algorithm but please give it a new function name! (The old one has stood the test of time.)