Created by: andrewscofield
These are useful in situations where you have a layout like at the top of the Narrow Jumbotron Template:
http://getbootstrap.com/examples/jumbotron-narrow/
If the navigation on the top right had the below .pull-right-sm it would be a normal block level item up to the sm breakpoint, preventing the 'Project Name' from awkwardly folding up and wrapping.