ignore invalid XML data

• Acceptance Test - Add?:

  No

I was playing with privacy lists and they did contain comments. This lead to unpredictable behaviour of the server.
ftp://ftp.isi.edu/in-notes/rfc3920.txt 11.1 reads "it MUST ignore the data".
Wildfire 3.1 did ignore comments, this was not was the right beaviour
Wildfire 3.2 does something else, it "damages" the xmpp connection, it will be no longer possible to query the conference service and one needs to restart Spark to be able to use it again.
My test packet:
<iq from='lg@jivesoftware.com/spark' type='set' id='id1'>
<query xmlns='jabber:iq:privacy'>
<list name='testlist'>
<item action='allow' order='1' type='jid' value='conference.jivesoftware.com'>
<message/><iq/><presence-out/><presence-in/>
</item>
<!-- silly comment -->
</list>
</query>
</iq>