Improved "highlight node" effects and scrolling.
Improved "highlight node" effects and scrolling.

This addresses long-standing complaints about showing highlighted nodes
in the tree popup, by:
 - adding a pulsing effect to the orange highlight
 - padding internal/unlabeled nodes, so the highlight is visible
 - fixing the scroll-to-node behavior on modern browsers (tested in
   Firefox and Chrome)

OpenTreeOfLife/opentree,OpenTreeOfLife/opentree,OpenTreeOfLife/opentree,OpenTreeOfLife/opentree,OpenTreeOfLife/opentree,OpenTreeOfLife/opentree