ACL service to query ACL resources and privileges.

* _buildResources: Build ACL resources from database.

Change-Id: I8d738bad39b20a935b06dc4dae1fb39e95f525cb
Main entry point.

* Define root path and other constants.

Change-Id: I34ef550f4669d30da019e4aba1f5efd4f8341ab9