[css4-color] <number> in HSL

Since we're having discussions about simplifying HSLA/RGBA, how about 
allowing <number> for saturation and lightness (0-1) too? It currently 
only allows for percentages, so there's not going to be any conflict.

Example: hsl(60, .5, 1) as equivalent to hsl(60, 50%, 100%)

-- 
Lea Verou (http://lea.verou.me | @LeaVerou)