b13 - 2013-02-01

Highlights include:

• Added new RimLighting and Erosion materials. See the Fabric wiki page.
• Added hue and saturation properties to ImageryLayer.
• Added czm_hue and czm_saturation to adjust the hue and saturation of RGB colors.
• Added JulianDate.getDaysDifference method.

See the change log for a full list of changes