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

Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

Mark usage function as __dead2 in programs where it does not return

In most cases, usage does not return, so mark them as __dead2. For the
cases where they do return, they have not been marked __dead2.

Reviewed by: imp
Pull Request: https://github.com/freebsd/freebsd-src/pull/735

fortune, strfile: Improve validation of command-line arguments.

- Avoid potential overflow when parsing a percentage.
- Avoid truncation when copying file paths.

PR: 246050
Submitted by: Akos Somfai <akos.somfai@gmail.com> (original)
MFC after: 1 week

strcpy => strlcpy, strcat => strlcat

Reported by: Coverity
CID: 1006703 978863 1006745 1347163
Reviewed by: cem
MFC after: 3 weeks
Sponsored by: Spectra Logic Corp
Differential Revision: https://reviews.freebsd.org/D10192

Remove support of ancient (pre-8.0R, 800041) FreeBSD releases.

MFC after: 2 weeks

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