* gnu/services.scm (make-files->etc-directory)
(files->profile-d-entries): New procedures.
(etc-profile-d-service-type): New service type.
* doc/guix.texi (Service Reference): Document it.
* gnu/tests/base.scm (run-basic-test): Test it.
Change-Id: I45dde43a1b9603c3384b933ebd1d6e45dba146b9