SmackException (and it's subclasses) is for all errors/exceptions not
defined by any XMPP specification. XMPPException is now an abstract
class for all errors defined by the XMPP specifications.
Methods that involve an IQ exchange now either return the result, which
is obtained by IQ response, or they throw an XMPPErrorException if an IQ
error was the result of the IQ set/get. If there was no response from
the server within the default packet timeout, a NoResponseException will
be thrown.
XMPP SASL errors are now also reported accordingly.
SMACK-426
RFC4616 states that if the authorization identity (authzid) parameter is
null, then it is derived from the authentication
identity (authcid). Smack currently sets both, authzid and authcid, to
the username, resulting in auth attempts of
userid\0userid\0password
instead of
userid\0password
Which are different users on most systems (e.g. Kerberos).
We now set only SASLMechanism.authenticationId to username. The
authenticate(String, CallbackHandler) method does now not longer receive
the username, as it's send by the CallbackHandler.
This makes Smack more portable, as there are platforms that support the
XmlPullParser interface, but not MXParser (e.g. Android).
Also enable checkstyle check that MXParser is not used.