RIOT output subsystem merged into trunk : new writers enabled by default

git-svn-id: https://svn.apache.org/repos/asf/jena/trunk@1454694 13f79535-47bb-0310-9956-ffa450edef68
Tidy up after RIOT output merged into trunk.

git-svn-id: https://svn.apache.org/repos/asf/jena/trunk@1454699 13f79535-47bb-0310-9956-ffa450edef68