JCR-3742 - Have DB related dependencies as optional in jackrabbit-data

Applying modified patch from Amit Jain
-- Made derby and commons-dbcp as optional
-- Removed dependency on commons-collection as it is not required

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/trunk@1577422 13f79535-47bb-0310-9956-ffa450edef68