Workaround for flaky JDBC test

git-svn-id: https://svn.apache.org/repos/asf/jena/trunk@1556169 13f79535-47bb-0310-9956-ffa450edef68
Add context key for configuring filter inequality optimization (JENA-615)

git-svn-id: https://svn.apache.org/repos/asf/jena/trunk@1556170 13f79535-47bb-0310-9956-ffa450edef68
Add filter inequality to standard optimizer but must be explicitly enabled currently (JENA-615)

git-svn-id: https://svn.apache.org/repos/asf/jena/trunk@1556171 13f79535-47bb-0310-9956-ffa450edef68
Optimize the case of MINUS where there is only a single common variable (relates to JENA-615)

git-svn-id: https://svn.apache.org/repos/asf/jena/trunk@1556180 13f79535-47bb-0310-9956-ffa450edef68
Fix copyright

git-svn-id: https://svn.apache.org/repos/asf/jena/trunk@1556188 13f79535-47bb-0310-9956-ffa450edef68