Assume the element
<foo:bar xmlns='namespace' xmlns:foo='foo-namespace'/>
then the <bar/> element's namespace is 'foo-namespace', but the
default namespace is 'namespace'. And this is the namespace that
scopes into inner elements.
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.
