Fixed css for links in tree view
Added drag to pin checkbox to graph view
Tweaking graph resize behavior. 
Visual indicator of pinned nodes.
Place link labels in center of link and rotate them 180 degrees if the
source is to the right of the target
merged changes
Merge branch 'graph-view-dev' into tl-development

Conflicts:
	src/nodejs/public/css/treeLayout.css
	src/nodejs/public/js/STIXRelationshipGraph.js