title: Problems with GWTP mergelocales.py
body: <p>I'm trying to use the mergelocales.py script but I can't get it working.</p>
  
  <p>In my ui.xml (the one that I am using to test it) I have this locales:</p>
  
  <pre><code>&lt;ui:UiBinder xmlns:ui="urn:ui:com.google.gwt.uibinder"
      ui:generateFormat='com.google.gwt.i18n.rebind.format.PropertiesFormat'
      ui:generateKeys="com.google.gwt.i18n.rebind.keygen.MD5KeyGenerator"
      ui:generateLocales="en_US, es_ES"
      ui:defaultLocale="es_ES"
      xmlns:g="urn:import:com.google.gwt.user.client.ui"&gt;
  </code></pre>
  
  <p>Then I compile my project using "-extra extras" argument. This generates an "extras" directory in my project wich haves a folder called "myModule" and inside this folder are the generated .properties files:</p>
  
  <pre><code>/myproject/extras/myModule/com.mycompany.myproject.client.mvp.views.MyViewImplMyViewImplUiBinderImplGenMessages_en_US.properties
  /myproject/extras/myModule/com.mycompany.myproject.client.mvp.views.MyViewImplMyViewImplUiBinderImplGenMessages_es_ES.properties
  </code></pre>
  
  <p>Now, I am trying to run the mergelocales.py to get the LocalizableResources*.properties files and when I try to run:</p>
  
  <p>python2.5 ~/Downloads/mergelocales.py extras/myModule src/main/java/com/google/gwt/i18n/client/</p>
  
  <p>I get the following stack trace:</p>
  
  <pre><code>Skipping non-default locale in extra directory: com.mycompany.myproject.client.mvp.views.MyViewImplMyViewImplUiBinderImplGenMessages_en_US.properties
  Skipping non-default locale in extra directory: com.mycompany.myproject.client.mvp.views.MyViewImplMyViewImplUiBinderImplGenMessages_es_ES.properties
  Traceback (most recent call last):
    File "/Users/admin/Downloads/mergelocales.py", line 497, in &lt;module&gt;
      main()    
    File "/Users/admin/Downloads/mergelocales.py", line 131, in main
      mergeLocales( args[0], args[1] )
    File "/Users/admin/Downloads/mergelocales.py", line 466, in mergeLocales
      pathname = os.path.join( resourcesDir, defaultLocaleFilename )
    File "/System/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/posixpath.py", line 60, in join
      if b.startswith('/'):
  AttributeError: 'NoneType' object has no attribute 'startswith'
  </code></pre>
  
  <p>Is there something that I am missing to get this script working?</p>