This makes it possible to use a factory function to create a transport of the right type and not having to repeat the address when calling Transport.Connect()
* Add constants (enumlike) for stanza types
* NewIQ, NewMessage and NewPresence are now initialized with the Attrs struct
* Update examples
* Do not export backoff code. For now, we do not need to expose backoff in the documentation
* Make presence priority an int8
remicorniere