Add Octicons

Closes #24

Add [GitHub Octicons](http://octicons.github.com/) to GlyphSearch.

Created a quick crawler that creates the JSON file for GlyphSearch from the Octicons website, so should be easy to keep the data up-to-date. [octicons-glyphsearch-crawler](https://github.com/matiassingers/octicons-glyphsearch-crawler)

Sorry to @repat if he was already working on this.

Let me know if there is any problems. 
I guess @thomaspark need to run the `grunt index` task as well :smile: 

![screen shot 2014-06-30 at 17 04 29](https://cloud.githubusercontent.com/assets/938453/3427656/95c42a88-0035-11e4-9e88-d5e6a70e3c80.png)