always exec the concatfragments script as root when running as root

This is to allow the concatfragments script to be installed into a path that may not be accessible by a non-root user.
remove usage of resource defaults for file owner/permissions

In addition, the permissions of the fragment directory and files is now fixed and not world readable.
Merge pull request #91 from jhoblitt/exec_as_root_when_root

always exec the concatfragments script as root when running as root