the '-l <tblcols>' flag limits the number of columns that column(1) will
produce in -t mode.  this is syntax-compatible with the same option in
util-linux's column(1), but due to existing differences between the two
implementations, it's not semantically compatible.

as a side-effect, fix a pre-existing bug where empty fields could cause
incorrect output:

	% echo ':' | column -ts:
	(null)

while here, also fix a couple of minor existing issues.

Reviewed by:	des
Approved by:	des (mentor)
Differential Revision:	https://reviews.freebsd.org/D50290

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

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

CID: 271595, 275337, 1368743

Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.

Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by:	Jan Schaumann <jschauma@stevens.edu>
Pull Request:	https://github.com/freebsd/freebsd/pull/96

This is rather pedantic, as for most architectures it holds that
sizeof(type *) == sizeof(type **)

Found by:	clang static analyzer
Reviewed by:	ed
Differential Revision: https://reviews.freebsd.org/D4722