errata/article.xml:

errata/article.xml:
- Prune stale entries from 11.1-RELEASE.
- Add an xml:id for diff reduction.

hardware/article.xml:
- Add an xml:id for diff reduction.

installation/article.xml:
- Add an xml:id for diff reduction.

readme/article.xml:
- Fix a malformed URL and mailing list reference.

readme/article.xml:
- Update the xml:id to match that used by readme/article.xml
  for consistency.

release.ent:
- Update versions, and switch from 'snapshot' to 'release'.

security.xml:
- Remove reference to 10.x.

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation