Ehanced interaction and transition with investigating collapsed nodes

-Highlighting of edge and nodes pertaining to the current collapsed
node on mouseover; also, on mouse-click the halo persists and either a)
can be unclicked or b.) another collapse node click fades out the
current collpase node and fades in the new uncollapsed node and
highlighting
-linked highlighting of the nodes on the linked view
-2nd order edge distance and strength now encoded based on SOJ
-cleaned and simplified variables