MFC various moves of tools/regressions/ tests to the new infrastructure.

- r263220 Migrate tools/regression/sbin/ to the new tests layout.
- r263222 Add Makefile missed in r263220.
- r263226 Migrate tools/regression/{usr.bin/lastcomm,usr.sbin}/ to the new tests layout.
- r263227 Migrate most of tools/regression/usr.bin/ to the new tests layout.
- r263345 Expand tabs that sneaked in into spaces.
- r263346 Migrate tools/regression/usr.bin/make/ to the new tests layout.
- r263348 Add Makefiles missed in r263346.
- r263351 Migrate tools/regression/usr.bin/pkill/ to the new tests layout.
- r263388 Mark multi_test as requiring /usr/share/dict/words.
- r263814 Fix path to the run.pl script to let these tests run.
- r264742 Prevent building tests when bootstrapping make.

This is 'make tinderbox' clean.

Migrate tools/regression/usr.bin/pkill to the new tests layout.

Interestingly, the pkill tool lives in bin, not usr.bin. Haven't bothered
to check if this is because the tool moved or because the tests were
originally added in the wrong place.

Fix formatting.

Catch up with UNIX98-style PTY's.

Add tests for -t option with short tty name - pkill(1) should accept both
(eg. "ttyv0" and "v0").

Add regression tests for pkill/pgrep.

MFC after: 3 days