ARQ 2.0 beta

Just released the first ARQ 2.0 beta. This version is a complete implementation of the SPARQL query language, and also includes the ARQ featurs of custom property functions and free-text search. The plan is that this is the only beta. The big change is that it uses the SPARQL algebra for query execution, and there is a query optimizer to choose an execution strategy that makes this better than simple evaluation of the algebra operators. This makes ARQ up to date with where the workign group is going - that includes some changes of results to some queries, but, hopefully, these are restricted to queries that don't appear in the wild.