path_nextnode(ENTITY*,var node,var edge)
Finds the next node along a given edge.
pointer to an entity attached to a path.
node - number of the current node (1 == first node of the path).
edge - number of the edge (1 == first edge of the node).
Number of the node to which the given edge leads from the given node
or 0 if no such edge exists.
The nodes leading to the current node can be found by checking
all nodes (path_getnode) and using path_nextnode for determining
if an edge leads to the current node.
temp = path_nextnode(my, 1, 1);
path_scan, path_getnode, path_getedge