Update 10cols.css

Semantic rewrite of the <480px selectors.
Update 11cols.css

Semantic rewrite of the <480px selectors.
Update 12cols.css

Semantic rewrite of the <480px selectors.
Update 2cols.css

Semantic rewrite of the <480px selectors.
Update 4cols.css

Semantic rewrite of the <480px selectors.
Update 5cols.css

Semantic rewrite of the <480px selectors.
Update 6cols.css

Semantic rewrite of the <480px selectors.
Update 7cols.css

Semantic rewrite of the <480px selectors.
Update 8cols.css

Semantic rewrite of the <480px selectors.
Update 9cols.css

Semantic rewrite of the <480px selectors.
Merge pull request #1 from pestbarn/master

@media span cleanup pull