* drop items with gr:autosub="true" (these are JIDs who were never explicitly
added by the user)
 * drop items with gr:inv="A" (these are e-mail addresses an invitation has
been e-mailed to)
 * drop items with gr:alias-for != NULL (these are e-mail addresses who have
replied to an invite, and now have a different JID)
 * drop items with gr:t="H" (these are JIDs who the user has indicated via
webmail that they do not want to see via gtalk, although oddly the server still
allows them to see your presence)
 * allow items with gr:rejected="true" (these are addresses who have rejected a
subscription request, and are hence valid JIDs)
 * allow items with ask="subscribe" (these are JIDs we're waiting for a
subscription reply from)
 * allow items with subscription != "none" (these are JIDs we have a
subscription to, from or both)
 * drop the rest (these can only be e-mail addresses)