Clear grid / reset

Hey, i'm giving a try to your grid, nice work, but it's missing a key feature 

like that http://www.joshfry.me/blog/2013/05/13/omega-reset-for-bourbon-neat
or http://gridle.org/documentation#classes-clear-each-default-driver

so the last option could be removed & and replaced by a a clear/reset of the margin right