Another Bug on Join Dups

The following illustrates:

```xml
<?xml version="1.0" encoding="UTF-8"?>
<application xmlns="http://wadl.dev.java.net/2009/02"
             xmlns:foo="http://www.rackspace.com/foo/bar"
             xmlns:xs="http://www.w3.org/2001/XMLSchema"
             xmlns:atom="http://www.w3.org/2005/Atom">
    <resources base="http://localhost/">
        <resource path="y" type="#FOO"/>
        <resource path="x" type="#FOO #BAR"/>
    </resources>
    <resource_type id="FOO">
        <method name="POST">
            <request>
                <representation mediaType="application/xml" element="foo:bar">
                    <param name="stuff"
                           style="plain"
                           required="true"
                           path="/foo:bar/@junk"/>
                </representation>
            </request>
        </method>
    </resource_type>
    <resource_type id="BAR">
        <method name="POST">
            <request>
                <representation mediaType="application/xml" element="foo:foo">
                    <param name="stuff"
                           style="plain"
                           required="true"
                           path="/foo:foo/@junk"/>
                </representation>
            </request>
        </method>
    </resource_type>
</application>
```

Resource x has FOO and BAR joined, but y is left disconnected.

Strategy for fix:

1. Don't exclude duplicated nodes
2. Remove any disconnected nodes after the optimization stage