rest-dsl - CORS support doesn't work with Restlet 2.3

camel-restlet has upgraded to Restlet 2.3 (nice!), but this broke rest-dsl CORS support, because Restlet 2.3 no longer supports setting CORS headers via attributes. There are now API methods for these headers and attributes are ignored with a warning.

Example of the new API method:
http://restlet.com/technical-resources/restlet-framework/javadocs/2.3/jse/api/org/restlet/Response.html#setAccessControlAllowOrigin%28java.lang.String%29