This commit adds
- SmackReactor / NIO
- a framework for finite state machine connections
- support for Java 8
- pretty printed XML debug output
It also
- reworks the integration test framework
- raises the minimum Android API level to 19
- introduces XmppNioTcpConnection
Furthermore fixes SMACK-801 (at least partly). Java 8 language
features are available, but not all runtime library methods. For that
we would need to raise the Android API level to 24 or higher.
replaces DefaultExtensionElement which is now deprecated.
Also changes Stanza (and MultiMap) API so that there can be duplicate extension
elements, as this change is required for StandardExtensionElement and by
the XMPP standard.