MFC: r285482

MFC:	r285482
	A variable was misspelled resulting in chmod executing on the installer instead of on the target chroot

PR:	191402

MFC:	r285553
	make /var/audit its own dataset so it is not part of the OS boot environment

PR:	199864

MFC:	r285554
	Set a mountpoint on the root of the pool so user-created datasets have a mountpoint to inherit

MFC:	r285557
	Make bsdinstall's zfsboot script align partitions to 4k/1m when the user requests it

PR:	195174

Approved by:	re (gjb), brueffer
Relnotes:	yes
Sponsored by:	ScaleEngine Inc.

git-svn-id: svn://svn.freebsd.org/base/stable/10@285721 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f