CAY-1912 BatchQueryBuilder refactoring

collapsing translator methods to a single one...

git-svn-id: https://svn.apache.org/repos/asf/cayenne/main/trunk@1578296 13f79535-47bb-0310-9956-ffa450edef68
CAY-1912 BatchQueryBuilder refactoring

making BatchTranslator an interface
making trim function part of the interface

git-svn-id: https://svn.apache.org/repos/asf/cayenne/main/trunk@1578297 13f79535-47bb-0310-9956-ffa450edef68