Part of JENA-458.

Rework GraphTDB so that there is one class for graph views of the database.
Use as much of the machinery of ARQ general GraphView system while
still carrying around the necessary information for TDB SPARQL evaluation.

Graphs are still restricted to be within a transaction boundary.


git-svn-id: https://svn.apache.org/repos/asf/jena/trunk@1483446 13f79535-47bb-0310-9956-ffa450edef68