remove qualifying tags in .span selectors for built in grid so that we can use .span-n classes in form styles

oops, double commit last time; apply fixes to make select elements line up in IE7 with their labels, but no height fix

overhaul docs CSS since it was scalable, converted docs mastheads and footers to classes and HTML5 elements, add masthead to js docs page but make it slate so it looks cool and stands out