Refactor to separate general index code from specific use for a store

git-svn-id: https://svn.apache.org/repos/asf/jena/trunk@1622772 13f79535-47bb-0310-9956-ffa450edef68
Remove dummy files added to get svn to work

git-svn-id: https://svn.apache.org/repos/asf/jena/trunk@1622775 13f79535-47bb-0310-9956-ffa450edef68