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
Move extension relevant configuration options from SmackConfiguration to
the extension. Introduced disabledSmackClasses that can be configured
via a system property or configuration file.
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.
Also move ProviderConfigTest into core, since it tests core
functionality, nothing provided by extensions. Found the reason the test
was failing since the gradle migration (provider entry test.providers),
and activated it again. \o/
New API design as of SMACK-545
