JENA-779 : Rework TransformFilterPlacement.processExtendAssign.

This is the JENA-779-filter-extend_distinct.patch. Includes filter movement through distinct and reduced operators.

Includes refactoring code to remove duplication for a class of "op1" processing.




git-svn-id: https://svn.apache.org/repos/asf/jena/trunk@1624485 13f79535-47bb-0310-9956-ffa450edef68