Test existing behaviour for RDF filetype recognition.
Get file types from suffixes on names.
Move jar: URI handling into its own class.
Improve JarAwareParsedURI.
Use the the JAR-aware URI in the parser wrapper.

Sesame's SAXFilter#createBaseURI has some odd handling for
jar: URIs that means we can't rely on simple intercepting
setBaseURI() (it's had an extra ':' added by the time we get it)
so continue to override parse.
Add the same jar:-aware wrapper for the Turtle parser.
Fix test after Mac OS X directory change.
Recognise Turtle and N-Triples as RDF data.

Recognise these by filetype and use the appropriate parser. For now,
special treatment for relative URLs in jars prevents direct use of
the more general Rio.parse.
Parse data in Turtle and N-Triples.