Moar fix

Alright, i think i'm closing in.
hopefully these are the last™ big changes from myself :)
at least all tests are green (again, for the third time \*g\*).

**PRs**
node-xmpp/node-xmpp-core#30
node-xmpp/node-xmpp-client#34
node-xmpp/node-xmpp-server#33

i also ported the s2s PR (node-xmpp/node-xmpp-server#29) to the new code: node-xmpp/node-xmpp-server#32
@chris-rock could you spare some tests to let me know if i didn't f'ed up the merge and cleanup?