Migrate server framework to Fuseki

[Aklakan]

With Fuseki's Plugin System "Fuseki Mods" now ready it might be worthwhile migrating RPT's jetty-based server framework to Fuseki.
This way, our sparql plugins that incubated in RPT can be directly implemented as Fuseki Mods and conversely, Fuseki Mods can be launched with RPT.

• RPT: command line tool for ad-hoc processing of RDF data, especially for rapid prototying; but not meant to be run as a permant sparql server.
• Fuseki: Long running production setups