2nd attempt at an inline-block solution

This commit swaps out float for column layout with inline-block, removing the need to clearfix the parent and child elements. 

As my previous method, setting a negative margin on .column(), broke .push() this method uses a negative letter spacing on .row() to kill whitespace in inline-blocked .column() elements.

Quickly tested, with .push also, in IE8/9/10 and Chrome and Firefox (current versions).