[weld-dev] Cleaning up weld core master

I'm going through testing the current CDI 3.0.0-RC1 TCK in preparation for the final release, and there are old integrations like org.jboss.weld.environment.gwtdev that rely on a jetty-6 release for GWT stuff. This will not work under the EE9 api change, so I'm going to remove it. I'm also trying to update the tomcat and jetty support using the current EE 9 based releases. We don't have one for undertow yet, so I will disable that for now. Is there any other cleanup/reorg we want to do as part of this?