Rangboom Sharing Directory Layout

<root>/
    ...
    shares/
        grabats.rb.cfg              (rangboom snsa login information)
        grabats/
            empty/                  (unwritable directory currently shared by snsa)
            rangboom/               (mount point for fuse mount by snsa)
                rbgroup01/          (rangboom group directory shared to grabats)
                    rbuser01/       (rangboom user directory, exporting to rbgroup01)
                ...
                rbgroupnn/          (rangboom group directory shared to grabats)
                    rbusernn/       (rangboom user directory, exporting to rbgroupnn)

Typically, each rangboom share group consists of only the owner of the
group, with the same rangboom name as the group name, as follows:

    shares/
        grabats/
            rangboom/               (mount point for fuse mount by snsa)
                rbname01/           (rangboom group directory shared to grabats)
                    rbname01/       (rangboom user directory, exporting to group rbname01)
                ...
                rbnamenn/           (rangboom group directory shared to grabats)
                    rbnamenn/       (rangboom user directory, exporting to group rbnamenn)