More Design plus extra tidbits

Monolithic commit, my bad.
This addresses issues #8 #5 #6 

Changelog:
* New index page
* Old index page is now the about page (better for project forking)
* Index page has Average score, Worst offenders, and Top scorers
* Redesigned business show page.
  * Now with inspections and violations grouped together and in tables
  * Chartjs chart showing history (currently doesn't work with only one inspection)
* Probably some other stuff I'm forgetting

Screenshots:

![Screen Shot 2013-03-23 at 12 46 08 PM](https://f.cloud.github.com/assets/92603/294160/4d9bb8e4-93d9-11e2-9e3b-9a25859d5ccc.png)

![Screen Shot 2013-03-23 at 12 46 13 PM](https://f.cloud.github.com/assets/92603/294162/4db2a28e-93d9-11e2-978a-1860fb5e87e2.png)