Comment 4 for bug 698528

Wrote possible fix for the issue:
http://repo.or.cz/w/geda-gaf/werner.git?a=shortlog;h=refs/heads/bugfix_promote_attributes

* Accept the old syntax and add a new one to accept a scm list of strings.
* Print a deprecation warning for the old syntax.
* Convert both syntax variants internally into a GList.

Regards
Werner