Ganetiviz: Updated bundled cytoscape.js version to 2.0.4 (latest)

Cytoscape JS v2.0.4 is the latest version of Cytoscape JS and includes some important bug fixes. I have updated the bundled lib version in ganetiviz, ran all tests.  It works smooth.
Cross browser compatibility, (example) Scroll to zoom in ganetiviz now works well with Internet Explorer too, with the latest cytoscape updates.