Inline Extra Includes

This has several commits to tidy things up a bit:

* remove excess trailing comma in Gruntfile (Navid caught my mistake here: b4fcb7f585f7ea6c64e1a7b889977f05ab3b05c7.)
* restore outside margins to page (I commented this out to test that Grunt was working and forgot to uncomment it).
* I updated the HTML to match the [HTML Styleguide](https://github.com/antinodes/VotingInfoApp/wiki/HTML-Styleguide)

The more significant commit is the one where I inlined the includes, `header.html`, `pageHeader.html` and `footer.html`, from `index.html` in order to save us a few http requests. We're including those on every page anyway, so it seemed to make sense to just inline them in the main layout. The only parts right now — and that could change depending on Rob's design — that are dynamic are `.main-nav` and `.auth`, are for authenticated users.