stand: Remove ancient SCCS tags.

Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl script.

Sponsored by: Netflix

Remove $FreeBSD$: one-line sh pattern

Remove /^\s*#[#!]?\s*\$FreeBSD\$.*$\n/

loader: Change version calculation to be more consistent.

Use 1000 * major + minor when calculating the version number that
gets set in the Ficl environment or lua loader property. This allows
for more room if the minor number needs to go above 9.

Add loader.version property to lua loader.

Reviewed by: imp
Obtained from: Juniper Networks, Inc.
Differential Revision: https://reviews.freebsd.org/D39631

Fix stand/newvers.sh with zsh in sh mode

When building on macOS with sh==zsh, newvers.sh was producing an
unterminated string literal due to \\n being turned as a newline. Fix this
by using a here document instead.

Reviewed By: imp
Differential Revision: https://reviews.freebsd.org/D26036

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

Sponsored by: Netflix