Export the repository's contents as RDF into the Semantic Web.

This commits adds a module dspace-rdf. The module will convert the
metadata stored in DSpace into RDF. The converted data will be provided
over a webinterface and a SPARQL endpoint.
rdfの文字化けを修正
Uses jena version 2.12.0 and removes workaround for bug JENA-663.
RDFConfiguration: added a method to load comma separated config values.
Enhanced and renamed the DSORelationsConverterPlugin into SimpleDSOR...

Renamed the DSORelationsConverterPlugin into
SimpleDSORelationsConverterPlugin.
Overhault the Plugin: it can be configured now and it can create
multiple links per DSO Relation.
Uses all possible identifiers to generate URIs.

This commit enables dspace-rdf to use all PersistentIdentifiers minted
by DSpace and not only handles. It makes advantage of the changes
introduced to DSpace by DS-1990. Persistent Identifers should and will
be used as fully functional http URIs only (e.g. a DOI will be used in
the form http://dx.doi.org/<doi> and not as doi:<doi>).
The DSpace Matadata Mapping vocabulary moved to digital-repositories.org
Repaired the build process after rebasing.

The dspace rdf war project wasn't build anymore as the activation of the
modules changed with the Mirage 2 contribution.
Enhanced the dspace-rdf command line interface.

Added the RDFizer to the launcher.xml configuration.
Added a command --convert-all.
Prints help if no options were given instead of starting reconvertion of
all content (which may take a lot of time).
Uses DSpace Repository Ontology from digital-repositories.org.
Changed the CLI help for conformance with launcher script name.
Repackaging: moved everything into dspace-api except the webapp.

The modules dspace-rdf contains the webapp to provide the converted data
as rdf serialization only. Everything else (classes for conversion,
storage, content negotiation, ...) moved into dspace-api so it can be
used easily by every other part of DSpace.
Adds content negotiation to XMLUI.
Merge pull request #568 from pnbecker/dspace-rdf

DS-2061: Linked (Open) Data support for DSpace