Add in some responsive goodness

Ahh yes, since we're using 1140 we need to embrace a responsive future. I've started adding in some breakpoints and cleaning up some layout issues when the page is resized. What direction do you want to take this in terms of where the responsive css lives. We can either:

• Include everything in 1 style sheet and use the media queries to apply styles to whatever needs it
• Split each breakpoint's styles up into their own css document and include that in the info stylesheet[] key
• Use css media selectors in the stylesheet[] key and split up the css documents

I like the idea of keeping everything separate, but I'd like to see what you guys want to do with it. Right now I'm putting all of my changes in the css/styles.css file.