org.apache.sling.ide.eclipse-core should not import org.codehaus.plexus

git-svn-id: https://svn.apache.org/repos/asf/sling/branches/tooling-ide-vlt@1525581 13f79535-47bb-0310-9956-ffa450edef68
 org.apache.sling.ide.impl-resource should not require org.eclipse.ui

git-svn-id: https://svn.apache.org/repos/asf/sling/branches/tooling-ide-vlt@1525582 13f79535-47bb-0310-9956-ffa450edef68