Fix incompatibility with latest Chrome version

• Use Object.keys() instead of our own hacky implementation of keys() in js/utils.js.

Update dependencies and recommend Google Chrome as primary browser

• Updated jQuery to v1.11.3
• Updated Highcharts to v4.1
• Incorporate @garfieldnate's fixes for Chrome compatibility.
• Additional fixes to get things working with Chrome.
• Make Google Chrome the recommended browser in the README.

New Highcharts library and minor bug fixes.

• Fixed whitespace trimming bugs (reported by Junhui Li from DCU)
• Fixed tokenization bugs.
• Updated highcharts library to latest version (3.0).