Screen for PDF action not found by turbine in XDAT

To recreate:

1. Modify the MR session data type in the admin view (Administer > Data Types) to include a new Report Action. This action should have name 'pdf'.
2. Go to an MR session in your XNAT.
3. Click the PDF action in the actions box (the name will depend on what you called it).
4. This will result in an error. Check the logs:
   1. turbine.log should contain this: {code}
      java.lang.ClassNotFoundException:
      
      Requested Screen not found: XDATScreen_pdf
      Turbine looked in the following modules.packages path:
      [org.apache.turbine.app.xnat.modules, org.nrg.xnat.turbine.modules, org.nrg.xdat.turbine.modules, org.apache.turbine.app.xnat17.modules, org.apache.turbine.modules]
      
      at org.apache.turbine.modules.ScreenLoader.getInstance(ScreenLoader.java:196)
      at org.apache.turbine.modules.pages.DefaultPage.doBuild(DefaultPage.java:142)
      at org.apache.turbine.modules.Page.build(Page.java:56)
      at org.apache.turbine.modules.PageLoader.exec(PageLoader.java:104)
      at org.apache.turbine.Turbine.doGet(Turbine.java:796)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:731){code}

      This makes it look like the XDATScreen_pdf.class is missing (or not under these packages).

   2. Double check this to see if it really is the case: go to WEB-INF/libs under the webapp, and run {code}
      unzip -v core-1.7.3-SNAPSHOT.jar | grep pdf{code}

      This will return something like:

      {code}
      6545 Defl:N 3063 53% 03-07-2017 15:12 32b0b4a9 org/nrg/xdat/turbine/modules/screens/XDATScreen_pdf.class{code}

      Huh....that's weird.

I've recreated this on both cnda-dev-jenny8 and xnat-dev03