Remove resource binding out of sasl auth

Follow XEP-170 recommendations: Resource binding *after* compression.

Fixes also a bunch of race conditions related to the wait()/notify()
pattern used in the early stages of a Connection where
createPacketCollectorAndSend(Packet).nextResultOrThrow() can not be
used. Those wait()/notify() patterns are currently
- SASL authentication
- compression
- resource binding

Fixes SMACK-454
No need to synchronize bindingRequired

If binding is required or not is told the client by the server within
the features stanzas. Smacks guarantees that connect() blocks until the
features stanzas has been received and processed.