Overlay Grid using Heads-Up plugin

[Emile Zola]

I've been using Heads-Up overlay grid plugin lately (
http://bohemianalps.com/tools/grid/) and I thought I'd share the config to 
make it work with the default bootstrap responsive grid. The code is pretty 
simple and straight-forward, so it should be pretty easy to customize. Here 
the gist : https://gist.github.com/2205275