Cleaned up IQPEPHandler and removed nodeID hierarchical renaming semantics in PubSubEngine (which conflicted with PEP [see 12.12 of XEP-0060 as to why it could be safely removed]).

git-svn-id: http://svn.igniterealtime.org/svn/repos/openfire/branches/pep@8821 b35dd754-fafc-0310-a699-88a17e54d16e