Selection plugin: cannot create Valuelist document in 7.9

In CMS 7.9 it is not possible to create a Valuelist document.

Steps to reproduce:

1. add the selection plugin to the archetype project by adding the following dependencies to cms/pom.xml:

<dependency>
<groupId>org.onehippo.forge.selectionplugins</groupId>
<artifactId>selectionplugins-addon-repository</artifactId>
</dependency>

<dependency>
<groupId>org.onehippo.forge.selectionplugins</groupId>
<artifactId>selectionplugins-addon-cms</artifactId>
</dependency>

2. rebuild the project and start the CMS
3. login as admin
4. create a new document of type 'Valuelist' and click 'OK'

Expected: a new valuelist is created
Actual: the CMS says "An error occurred, please retry". The following exception is logged:

[INFO] [talledLocalContainer] 01.05.2014 15:46:09 WARN http-bio-8080-exec-12 [FolderWorkflowPlugin.select:432] Invalid workflow configured for node of type hippo:handle in category 'editing'; expected an EditableWorkflow implementation
[INFO] [talledLocalContainer] 01.05.2014 15:46:09 ERROR http-bio-8080-exec-12 [AbstractWorkflowDialog.onOk:59] Could not execute workflow.
[INFO] [talledLocalContainer] java.lang.NullPointerException
[INFO] [talledLocalContainer] at org.hippoecm.frontend.plugins.standardworkflow.FolderWorkflowPlugin.select(FolderWorkflowPlugin.java:436)
[INFO] [talledLocalContainer] at org.hippoecm.frontend.plugins.standardworkflow.FolderWorkflowPlugin$4.execute(FolderWorkflowPlugin.java:320)
[INFO] [talledLocalContainer] at org.hippoecm.frontend.plugins.standardworkflow.FolderWorkflowPlugin$4.execute(FolderWorkflowPlugin.java:272)
[INFO] [talledLocalContainer] at org.hippoecm.addon.workflow.StdWorkflow.execute(StdWorkflow.java:219)
[INFO] [talledLocalContainer] at org.hippoecm.addon.workflow.StdWorkflow.execute(StdWorkflow.java:207)
[INFO] [talledLocalContainer] at org.hippoecm.addon.workflow.StdWorkflow.invokeWorkflow(StdWorkflow.java:236)
[INFO] [talledLocalContainer] at org.hippoecm.addon.workflow.AbstractWorkflowDialog.onOk(AbstractWorkflowDialog.java:54)
[INFO] [talledLocalContainer] at org.hippoecm.frontend.dialog.AbstractDialog.handleSubmit(AbstractDialog.java:519)
[INFO] [talledLocalContainer] at org.hippoecm.frontend.dialog.AbstractDialog$2.onSubmit(AbstractDialog.java:277)
[INFO] [talledLocalContainer] at org.hippoecm.frontend.dialog.ButtonWrapper$1.onSubmit(ButtonWrapper.java:80)
[INFO] [talledLocalContainer] at org.apache.wicket.ajax.markup.html.form.AjaxButton$1.onSubmit(AjaxButton.java:108)
[INFO] [talledLocalContainer] at org.apache.wicket.ajax.form.AjaxFormSubmitBehavior$1.onSubmit(AjaxFormSubmitBehavior.java:179)
[INFO] [talledLocalContainer] at org.apache.wicket.markup.html.form.Form.delegateSubmit(Form.java:1266)
[INFO] [talledLocalContainer] at org.hippoecm.frontend.dialog.AbstractDialog.delegateSubmit(AbstractDialog.java:527)
[INFO] [talledLocalContainer] at org.apache.wicket.markup.html.form.Form.process(Form.java:938)
[INFO] [talledLocalContainer] at org.apache.wicket.markup.html.form.Form.onFormSubmitted(Form.java:770)
[INFO] [talledLocalContainer] at org.apache.wicket.ajax.form.AjaxFormSubmitBehavior.onEvent(AjaxFormSubmitBehavior.java:156)
[INFO] [talledLocalContainer] at org.apache.wicket.ajax.AjaxEventBehavior.respond(AjaxEventBehavior.java:123)
[INFO] [talledLocalContainer] at org.apache.wicket.ajax.AbstractDefaultAjaxBehavior.onRequest(AbstractDefaultAjaxBehavior.java:626)
[INFO] [talledLocalContainer] at sun.reflect.GeneratedMethodAccessor81.invoke(Unknown Source)
[INFO] [talledLocalContainer] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
[INFO] [talledLocalContainer] at java.lang.reflect.Method.invoke(Method.java:606)
[INFO] [talledLocalContainer] at org.apache.wicket.RequestListenerInterface.internalInvoke(RequestListenerInterface.java:258)
[INFO] [talledLocalContainer] at org.apache.wicket.RequestListenerInterface.invoke(RequestListenerInterface.java:241)
[INFO] [talledLocalContainer] at org.apache.wicket.core.request.handler.ListenerInterfaceRequestHandler.invokeListener(ListenerInterfaceRequestHandler.java:250)
[INFO] [talledLocalContainer] at org.apache.wicket.core.request.handler.ListenerInterfaceRequestHandler.respond(ListenerInterfaceRequestHandler.java:236)
[INFO] [talledLocalContainer] at org.apache.wicket.request.cycle.RequestCycle$HandlerExecutor.respond(RequestCycle.java:862)
[INFO] [talledLocalContainer] at org.apache.wicket.request.RequestHandlerStack.execute(RequestHandlerStack.java:64)
[INFO] [talledLocalContainer] at org.apache.wicket.request.cycle.RequestCycle.execute(RequestCycle.java:261)
[INFO] [talledLocalContainer] at org.apache.wicket.request.cycle.RequestCycle.processRequest(RequestCycle.java:218)
[INFO] [talledLocalContainer] at org.apache.wicket.request.cycle.RequestCycle.processRequestAndDetach(RequestCycle.java:289)
[INFO] [talledLocalContainer] at org.apache.wicket.protocol.http.WicketFilter.processRequestCycle(WicketFilter.java:259)
[INFO] [talledLocalContainer] at org.apache.wicket.protocol.http.WicketFilter.processRequest(WicketFilter.java:201)
[INFO] [talledLocalContainer] at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:282)
[INFO] [talledLocalContainer] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
[INFO] [talledLocalContainer] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
[INFO] [talledLocalContainer] at org.hippoecm.frontend.plugins.login.ConcurrentLoginFilter.doFilter(ConcurrentLoginFilter.java:54)
[INFO] [talledLocalContainer] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
[INFO] [talledLocalContainer] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
[INFO] [talledLocalContainer] at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
[INFO] [talledLocalContainer] at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
[INFO] [talledLocalContainer] at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
[INFO] [talledLocalContainer] at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
[INFO] [talledLocalContainer] at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
[INFO] [talledLocalContainer] at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
[INFO] [talledLocalContainer] at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
[INFO] [talledLocalContainer] at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
[INFO] [talledLocalContainer] at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040)
[INFO] [talledLocalContainer] at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607)
[INFO] [talledLocalContainer] at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:315)
[INFO] [talledLocalContainer] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
[INFO] [talledLocalContainer] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
[INFO] [talledLocalContainer] at java.lang.Thread.run(Thread.java:744)