#358 Have dropdown menu for concept and mapping node expansion menus. This was really way trickier than it should have been, fussing with svg and jquery disagreements (so use D3 isntead for all SVG stuff), and remembering to use mouseleave rather than mouseout. The methods called when we click dead-end because the callback used has indeed already been fulfilled. Looking at whether this is a design issue of the REST cache...I suspect it is.
#358 Have concept and mapping expansions working. Tweaked that menu.
#358 Fixed NaN bug on nodes. It was tough to track down, but it was due to ids on edges not being unique since I added the composite edge types.
#358 Fixed bug with expanded arcs not showing up until they were dragged.
#358 Fixed mapping expansion of nodes by defending against bad data that caused an infinite loop (self reference, and maps not involving source). Reduced edges therein to one per pair. Fixed infinite loop in child REST fetches.
#358 Fixed mapping temporary edge rendering. When I refactored the edge and node highlighting a few commits back, I totally failed to see the method I had recently made, and refactored that method call by deleting it. Oops.
Merge branch 'issue330_d3layout'
#330 Changed SVG ids used in layouts to match new ones, for merge.
#330 Missed some commits because I didn't pull prior to merging. I might have broken something. Here is the missing commits merged.
Merge branch 'master' into issue330_d3layout