Align with HTML5 Boilerplate

This is a minimal alignment to avoid any clashes.  In summary:

* index.html modified with meta tags and browsehappy warning for <IE8 users
* added robots.txt
* added crossdomain.xml
* added humans.txt and modified to reflect EAK technologies

I did not bother with any JS related items (Modernizr and jQuery), as EAK developers will likely have a specific set of JS project requirements to suit their own tastes.  I also did not copy the Google Analytics snippet as GA requires a little extra attention when dealing with Ember, and not sure if EAK wants to be opinionated on visitor tracking services anyway.

I did not copy over favicon or the Apple touch icon as these are H5BP branded.  I figure once the matter of [EAK's logo](https://github.com/stefanpenner/ember-app-kit/issues/197) is sorted out, we can add these final boilerplate items.


Resolves #339