Feature/grid

[hochitom]

i added a parameter to the grid mixin to avoid creating unneeded grid classes. i hope i can fulfill your contributing requirements ;)

[emagnier]

Cool, I made 2 similar PRs on the Inuit.css v6 alpha:

• Uses a mixin to generate all widths inuitcss/trumps.widths#2
• Add Media Queries support, and re-introduce the one-whole width. inuitcss/trumps.widths#3

It keeps the retrocompatibility with Inuit.css v5, but needs Sass 3.3.

The generated code is still clean and readable, if necessary the width selectors extend between themselves, and you can specify only the width family you want, e.g.: $widths: 1, 2, 3, 6, 12, 16.