Connect morphology skeletons with multiple partitions.

[marwan-abdellah]

To be able to reconstruct a single neuronal morphology skeleton, we must connect the multi-partition graphs into a single connected graph. If the graph is composed of two partitions, then find the termional 'unconnected' samples and then connect them. Incase the graph has more partitions, we will find the parent partitions (that has the highest number of samples) and then start connecting the other partitions.