Provide a command-line app with embedded Jetty

[cygri]

Provide a command-line application that allows quickly starting up a Pubby server without the need for a pre-installed servlet container. This would be great for testing, development, etc.

Possible example invocations:

• pubby --config config.ttl
• pubby --load somefile.rdf
• pubby --sparql http://dbpedia.org/sparql

From a packaging point of view, if we want to do this with Maven, it probably requires a separate Maven project, making everything quite a bit more complicated.