Remove $FreeBSD$: two-line nroff pattern

Remove /^\.\\"\n\.\\"\s*\$FreeBSD\$$\n/

check-password.4th(8): Fix manual [in]accuracy

SVN r280384 updated the maximum password length from 16 bytes to 255. The
manual was not updated to reflect this. Found while working on kern/207069.

MFC after: 3 days
X-MFC-to: stable/11 stable/10
Sponsored by: Smule, Inc.

Move sys/boot to stand. Fix all references to new location

Sponsored by: Netflix