Change name and links from Dell KACE to Quest KACE.

Dell decided in October 2016 to sell off the Dell Software Group to venture
capitalists wherein Quest Software became a separate Business Unit
encompassing the KACE product line. The deal was completd on November 1, 2016
with them becoming Quest Software. Change the name and URL in the handbook
to the new owners accordingly.

Reported by: David.Holcomb@quest.com (via freebsd-doc)