JCR-3751 -  S3Backend fails to initializate from file system based configuration file

Applying patch from Shashank. Thanks!



git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/trunk@1578774 13f79535-47bb-0310-9956-ffa450edef68
add access control mgt support for jcr2spi