Redo build system. Fixes #21

Fixes #21.

Greatly simplified build process for site. This should make it much easier for users to contribute.

Edit configs and re-arrange assets a little bit to take advantage of GitHub's support for Jekyll 2.2.0.

Totally ripped out bower and moved frontend dependences to submodules.

Removed gruntfile. Got rid of package.json.

Edit URLs for assets in HTML to not use the main site URL.

Get rid of dev jekyll config.

Added documentation to README to document how to get the project running on your local machine.