Replaced hard-coded http protocol in JS lib links

Also updated d3 from 2.9.6 to 2.10.0 (due to availability over public, https-supporting CDN) -- hopefully that doesn't break anything.

See https://github.com/Pivotal-Field-Engineering/PCF-demo/issues/2

Note: haven't tested yet due to maven failing over the poor wifi here at http://www.pivotal.io/platform-as-a-service/cloud-platform-roadshow/minneapolis