Remove copyright strings ifdef'd out

We've ifdef'd out the copyright strings for some time now. Go ahead and
remove the ifdefs. Plus whatever other detritis was left over from other
recent removals. These copyright strings are present in the comments and
are largely from CSRG's attempt at adding their copyright to every
binary file (which modern interpretations of the license doesn't
require).

Sponsored by: Netflix

usr.bin: 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

Purge more stray embedded $FreeBSD$ strings

These do not use __FBSDID but instead use bare char arrays.

Reviewed by: imp, emaste
Differential Revision: https://reviews.freebsd.org/D41957

Fix the way 'factor' behaves when using OpenSSL to match the description
of how it works when not compiled with OpenSSL.

Also, allow users to specify a hexadecimal number by using a prefix of
'0x'. Before this, users could only specify a hexadecimal value if that
value included a hex digit ('a'-'f') in the value.

PR: 243136
Submitted by: Steve Kargl
Reviewed by: gad
MFC after: 3 weeks

Use capsicum helpers to cache NLS data.

Convert `cap_enter() < 0 && errno != ENOSYS` to `caph_enter() < 0`.

No functional change intended.

Using results from
J. Sorenson and J. Webster, Strong pseudoprimes to twelve prime
bases, Math. Comp. 86(304):985-1003, 2017.
teach primes(6) to enumerate primes up to 2^64 - 1. Until Sorenson
and Webster's paper, we did not know how many strong speudoprime tests
were required when testing alleged primes between 3825123056546413051
and 2^64 - 1.

Reported by: Luiz Henrique de Figueiredo
Relnotes: primes(6) now enumerates primes beyond 3825123056546413050,
up to a new limit of 2^64 - 1.
MFC After: 1 week

primes: trivially capsicumize

Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D7982

Final step of eliminating the "games" distribution: Merge src/games
(or what's left of it, at least) into src/usr.bin.

This change will not be MFCed.

Discussed at: EuroBSDCon 2014
Committed from: EuroBSDCon 2015