Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Use = not == in test arguments.

Submitted by: Christoph Mallon <christoph.mallon@gmx.de>

Implement the -l option using ln(1) to facilitate boostrapping.

Ignore the new options -D, -h, -T, and -U. Adjust -M support to ignore
an argument.

Sponsored by: DARPA, AFRL
Reviewed by: ian, ray, rpaulo

Teach tools/install.sh the -d directory mode.

Sync up with flags understood by install(1) [1], and make install(1)'s
usage output not hide the clearly documented -M flag.

PR: misc/154739 [1]
Submitted by: arundel

Arguments to options aren't necessarily separated with whitespace.

Noticed by: harti

From what I can tell, install.sh supported all of the install(1)
options since revision 1.2, so removed the XXX comment now.

Fixed bogus test(1) expression that would be evaluated as a null
string test if script is run without arguments, compacted option
lists.

Fix typo in the BSD copyright: s/withough/without/

Spotted and suggested by: des
MFC after: 3 weeks

Added support for all new install(1) options.
Removed -c from the actual call as -p implies "copy".

Don't use -C internally. Use -c. For some reason files are not copied
with -C, although they should.

Use install -C -p instead of cp -p.

Pointed out by: bde

install(1) lookalike that can be used during a build. Any options
are ignored and the remaining is passed on to cp(1). This allows
a build to be run as non-root without forcing any user/group
setting and also prevents setting any file flags.

This may not be the right place for buildtools.