Remove entry for HKS, Incorporated.  Site has been vacant for years.

PR:		194850
Submitted by:	Wes <ellisgen@gmail.com>
Document __FreeBSD_version numbers 1100045, 1001502,
903506, 804507.

Sponsored by:	The FreeBSD Foundation
Wrap a line that was making my brain itch.

Sponsored by:	The FreeBSD Foundation
In the section on re-adding a deleted port, clarify what addport is and
link back to the section where it is described.  Also clean up some of
the language in that first section.