Connectivity: make OR default, and rename to "All partners".
AND becomes "Common partners".

Makes sense to have OR as default given the "append" button.
Fix error in Selection Table.
Update to cytoscape.js 2.0.2

Remove as well from index.html the line loading the old graph_widget.js.
Graph: preserve position of existing nodes when loading further nodes.

Additionally:
 * added extra layout modes and a button to re-layout.
 * moved event triggers to init function where they belong.
Object Tree: provide a pulldown menu to choose a source,
but default to opening a new selection table associated with a 3d view
when none is selected.
Graph: restore node css upon finishing the highlight animation.
Connectivity: add missing function removeSkeletons
Graph: set white background.
Merge remote-tracking branch 'origin/master' into neurocity
For a given skeleton, fetch all underlying tiles into the local client cache