Better landing page template + wireframed modules landing page

### Adding ability to have sub styles of the landing page
Front-matter example:

	---
	layout: landing
	sub-style: {SubStyleName}
	---

CSS Naming:

	/css/{SubStyleName}.landing.css

### Adding landing page w/ modules similar to wireframes.

Utilizes sub styles mod added in commit 8782c2a to produce a landing
page that resembles the wireframe found at http://bit.ly/1gvtEBG

	/modules.landing.html