Log Message:
Update to 0.9.21:

2010-12-04 Rasqal Version 0.9.21 Released

   Updated to handle aggregate expression execution as defined by the
   SPARQL 1.1 Query W3C working draft of 14 October 2010
   Executes grouping of results: GROUP BY
   Executes aggregate expressions: AVG, COUNT, GROUP_CONCAT, MAX, MIN,
   SAMPLE, SUM
   Executes filtering of aggregate expressions: HAVING
   Parses new syntax: BINDINGS, isNUMERIC(), MINUS, sub SELECT and
   SERVICE.
   The syntax format for parsing data graphs at URIs can be explictly
   declared.
   The roqet utility can execute queries over SPARQL HTTP Protocol and
   operate over data from stdin.
   Added several new APIs
   Fixed Issue: #0000388