showcase: xml-apis-ext is needed for GWT compile
showcase: xml-apis-ext is needed for GWT compile

Without this change the xml-apis-ext would only appear on the runtime
classpath (transitively via jbpm-designer-backend). GWT compilation
needs to the dependency to be on compile classpath.

droolsjbpm/jbpm-console-ng,etirelli/jbpm-console-ng,droolsjbpm/jbpm-console-ng,annabaker/jbpm-wb,annabaker/jbpm-wb,etirelli/jbpm-console-ng,nmirasch/jbpm-console-ng,droolsjbpm/jbpm-wb,nmirasch/jbpm-console-ng,droolsjbpm/jbpm-wb