Fixes and tests for JENA-422

Allows for top level BIND to round trip (albeit as a project expression but it's semantically equivalent)
Fixes the reported issue of BIND inside a SERVICE clause not being carried to the remote service

git-svn-id: https://svn.apache.org/repos/asf/jena/trunk@1460878 13f79535-47bb-0310-9956-ffa450edef68