JRDF 0.5.5.5

It's been a long while between updates but it's finally here. There's been some general concessions made to long standing "features" in JRDF namely relational semantics and checked exceptions - both are gone. Yuan-Fang added merge-join support which improved join performance (by up to 8 times). There's Groovy support and a nasty memory leak fixed. It's in the usual place. The next version won't be so far away with some further SPARQL query improvements including perhaps some of the newly proposed features.