The jingle subproject builds now. This doesn't change that the code is
outdated with regard to the specification and unmaintained for
years. But hopefully this is the first step to change that. :)
The integration tests have been moved into SourceSets of 'core' and
'extensions'.
The initializer tests verify that every non-optional initializer, this
includes Providers, is loadable.
Creating files under META-INF is not considered best practice. Smack's
configuration and provider files reside now in classpath directory
qualified by Smack's package namespace.