Add Bootlint to build

# DO NOT MERGE

Adds https://github.com/twbs/bootlint checking for making sure Bootstrap conventions are followed

- [ ] Cleanup `col-*` markup
- [ ] Add to base grunt task and rebase
- [ ] Exclude server pages since they don't use the same setup right now
- [ ] Probably don't need to lint both min and unmin
@nschonni Okay. Technically it is a failure of Bootstrap's rules but I don't see any need to change the markup for this for the following reasons:
* Conflicts with using hidden headers (so no practical effect on the grid system or any page display but is still invalid according to Bootlint)
* Affects the positioning of the menu. Adding col-xs-12 to the child container will force a gutter we don't want and then force us to override Bootstrap CSS to remove that gutter. So to pass Bootlint we would need to add unnecessary markup and CSS.

I'm assuming the relaxerror option disables those errors which would meet our needs here.