title: GWT - adding external java classes to client project
body: <p>I have a GWT project. Client code is located in the "client" dir. I want to attach an external java classes (mainly plain POJO DTO classes) that are in external directory. How to configure the gwt.xml file?</p>
  
  <p>I get errors of this kind:</p>
  
  <p>[ERROR] Errors in 'file:/C:/development/projects/CodeSpaces/LocateMe/LocateMeWeb/src/com/dominolog/locateme/client/LocateMeWeb.java'
                 [ERROR] Line 56: No source code is available for type com.dominolog.locateme.model.dto.LocationInfo; did you forget to inherit a required module?</p>