Put ability to chose PrefixMapping implementation into GraphBase.
Remove GraphBase2.


git-svn-id: https://svn.apache.org/repos/asf/jena/trunk@1441967 13f79535-47bb-0310-9956-ffa450edef68
Put ability to chose PrefixMapping implementation into GraphBase.
Remove GraphBase2.


git-svn-id: https://svn.apache.org/repos/asf/jena/trunk@1441968 13f79535-47bb-0310-9956-ffa450edef68