2015-06-18

Enhancements:
 - Handles coordinates out of range errors returning an empty image
 - Blend rendering fallback to empty image when http layer request fails
 - Checks the type of torque-specific CSS rules
 - Unifies error response format to `{ "errors": ["messages"] }`

Announcements:
 - Removes LocalizedResourcePurger to avoid issues with cached assets
   See https://github.com/CartoDB/Windshaft/issues/339#issuecomment-104684003