Added support for HSLA colors in geojson properties.
Added comment about expected range for values of h,s,l, and a.
hsla colors now expect hues from 0-360. Also added some more comments regarding what ranges various Color.js functions expect.
Moved divide by 360 logic from Color.parse() to hsla2rgb(). Added multiply by 360 logic to Color.toHSLA().
Removed meaningless 'base' parameters from calls to parseFloat().
Merge pull request #31 from bennlich/master

enabling HSL colors