Added karma-telemetry for performance analysis

Added telemetry using karma-telemetry project to generate performance results for various browsers. This can be run in addition to the grunt telemetry task to collect data from other browsers too. 

**Tested it on Window 8.1 [IE 11, Firefox 25, Chrome 31] and Mac [Firefox 25, Chrome 31]**

To try out this task, run `grunt karma-perf`. Ensure that Karma can run IE, Firefox and Chrome. For non-windows platform, disable IE in `Gruntfile.js`. Performance results are generates as `dev/test/perf/karma/*.xml`.

__Note__: `karma-submit` task is still incomplete as the format that the server needs these results is unknown. This pull request has a stub for the submit and the actual content needs to be filled in.