allow disperse transitions for petri nets

[Dan Bean]

possibly restrict to only allowing coarse transitions to be disperse

could treat transitions exactly as places and allow them to be disperse, pooling the input and output edges for disperse transitions that are not also coarse (we would have to add somewhere that this is really not recommended).

This will have quite widespread affects as the logic of most functions assumes transition nodes are unique. It does already work for exporting matrices if name changed from dev tools for a very simple network.