Add the announce.xml file.

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation
Add the PGP-signed announcement.

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation
Connect announce.xml and announce.asc to the build.

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation
Announce 10.1-RELEASE.

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation
Turn off the where.html download links for 10.1-RC4.
Update the current 10.x release to reflect 10.1.

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation
Comment the 'Upcoming Release Schedule'.
Update the 10.1 schedule to reflect 10.1-RELEASE is
available.

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