Drop grunt-recess for grunt-contrib-less

This is the first part to migrating away from Recess and to something that's more up to date with LESS. It adds a few other dependencies, and there are some kinks to work out though.

* Drops `grunt-recess` and adds `grunt-contrib-less`.
* Adds CSScomb for property ordering (non functional for some reason right now—halp?).
* Requires addition of `grunt-banner` though since `grunt-contrib-less` hasn't implemented (and won't) banner support.

We'll need to integrate #11778 as part of this as well, either before or after. Perhaps @XhmikosR wants to join in on the fun here? Definitely could use some help.