Small change to popup help content
Added minZoom and maxZoom parameters
(initially set to 0.1x and 10x respectively)
Switched to using cytoscape JS recommended event binding style for solving mousdown problem over instances.
Check: https://github.com/cytoscape/cytoscape.js/issues/311
Updated Cytoscape JS libs to 2.0.2 (from 2.0.1)