ie 9 compatibility

Thanks for sharing .

I Tested it in Chrome,Firefox and it's OK , however it fails in IE9 silently .

This behaviour is due to IE9 not supporting JSON object by default .
This line of code fails localStorage.setItem(this.name, JSON.stringify(events));
We can load json2.js from a CDN:
http://cdnjs.cloudflare.com/ajax/libs/json2/20110223/json2.js to resolve the issue .

[jeremyharris]

Thanks for the report. I'll add a note in the readme about support for IE9.