Introducing Smack's own XmlPullParser interface which tries to stay as
compatible as possible to XPP3. The interface is used to either wrap
StAX's XMLStreamReader if Smack is used on Java SE, and XPP3's
XmlPullParser if Smack is used on on Android.
Fixes SMACK-591.
Also introduce JUnit 5 and non-strict javadoc projects.
and some further minor jingle fixes:
- deprecate getJingleTransport() in favor of getTransport()
- Jingle.Builder now checks if the session ID is not empty
- Change visibility of some Socks5Bytestreams code.
- Add central ThreadPool
- Move FullJidAndSessionId in own class
- More complete JingleSession class
- More complete JingleUtil class
- Improved tests