functions for making the root rom directory, and main rom folders.
the folders are created as follows:
enforce rom directory permissions - root:$user for roms folder with the sticky bit set,
and root:$user for first level subfolders with group writable. This allows them to be
writable by the pi user, yet avoid being deleted by accident

add a new module for reset existing rom folder permissions, which was previously done as part of samba shares, and make the samba shares
module call this instead