MFC revisions 256321-256323,256331,256333,256335,256343:
Bring in a new zfsboot auto script for performing automatic setup of a boot
pool (optionally encrypted) with many other options, validations, features.
Originally submitted by Allan Jude; modified in collaboration.

MFC revisions 256325,256330,256345:
Rewrite the keymap selection menu to display keymaps and provide a test
mechanism. Test mechanism originally submitted by Warren Block; modified.

MFC r256347:
Prominently display "Wireless" for each wireless network interface. Part
of PR bin/161547; submitted by Warren Block; slightly modified.

MFC r256348:
Remove the dumpdev configuration dialog, merge it into the regular
services configuration and enable it by default. Originally submitted by
Allan Jude; slightly modified.

PR:		bin/161547
Submitted by:	Allan Jude, Warren Block <wblock@wonkity.com>
In collaboration with:	Allan Jude <freebsd@allanjude.com>
Approved by:	re (glebius)