The 'rom_tar' service obtains a TAR archive via a ROM connection and, in turn,
provides the files contained in the TAR archive as individual ROM sessions.
The name of the TAR archive must be specified via the 'name' attribute of
an 'archive' tag, for example:

! <config>
!   <archive name="archive.tar"/>
! </config>

The backing store for the dataspaces exported via ROM sessions is accounted
on the 'rom_tar' service (not on its clients) to make the use of 'rom_tar'
transparent to the regular users of core's ROM service. Hence, this service
must not be used by multiple clients that do not trust each other.
