Document r271880, serial and null console support added to UEFI
boot loader.

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation
Document r271943, Latest/pkg.txz symlink included on the DVD to
make bootstrapping pkg(8) easier.

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation
Document r271947, OpenPAM updated to Ourouparia (20140912).

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