Manual part 2

adding the classes int the gwt.xml and inside the jars adding the class.xml file:
so there are two things to do, if adding a external library:
1. adding the class in the com.gwt.xml (projectname.gwt.xml) and
2. adding a classname.gwt.xml file with the name of the class inside

...more you can find here, how to handle eclipse and gwt:
http://www.vogella.com/tutorials/GWTModules/article.html
searching the net: >> Using external jars / Java projects in GWT <<

1.
com.gwt.xml:
add these lines, next to the lines of the neuroph classes:

  <inherits name='com.google.gwt.user.client.ui.Image'/>
  <inherits name='com.google.gwt.core.client.GWTBridge'/>

gwt-dev.jar: find and add GWTBridge.gwt.xml with
<module>
<inherits name="com.google.gwt.user.User"/>

</module>

gwt-user.jar:
<module>
<inherits name="com.google.gwt.user.User"/>

</module>