Distribute test cases in tarballs by default

* INSTALL, INSTALL.REPO, admin/make-tarball.txt:
Mention ‘make check’.
* configure.ac: Update comment.
* etc/NEWS: Say that tarballs have a test directory.
* make-dist (with_tests): Default to "yes".
Add an option --no-tests to make it "no".
1 job for master in 50 minutes and 36 seconds (queued for 3 seconds)
Status Job ID Name Coverage
failed #1777


Name Stage Failure
test-all Test
Makefile:318: recipe for target 'check-doit' failed
make[2]: Leaving directory '/builds/emacs/emacs/test'
make[2]: *** [check-doit] Error 1
Makefile:293: recipe for target 'check-expensive' failed
make[1]: *** [check-expensive] Error 2
make[1]: Leaving directory '/builds/emacs/emacs/test'
Makefile:957: recipe for target 'check-expensive' failed
make: *** [check-expensive] Error 2
ERROR: Job failed: exit code 1