[tei-council] Expiring specifications

[Martin Holmes]

Before the next release, we have

<relationGrp>: validUntil="2014-06-17"

It's referenced in five other specifications (listEvent, listNym, 
listOrg, listPerson, listPlace).

Since we won't be doing a release until well after the expiry date, is 
there any objection to removing it and cleaning up after it now? That'll 
allow a little time for any possible side-effects to emerge and be 
sorted out.

Cheers,
Martin