Workaround #662

  Add a fix amount to shift the regulator when regulator multimer is
  enabled.

  For multimers we do custom rendering. Cytoscape doesn't change node
  data (width, height or position) when doing this but it changes the
  bounding box of the node which causes edges to render tilted.
  Work around this for now by shifting the node to the side by a fixed
  amount.