Add tests from the old svn tree

We're losing the svn history (which we could probably keep if we tried
hard enough) but don't consider that worthwhile.

Note these tests are destructive, so run them only in a throwaway
environment like a chroot, container, or vm.

The tests/run.all script should be the one which launches all the tests.

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>

tests/grouptools/chgpasswd/08_chgpasswd_usage-e-m_exclusive/data/usage.out

@@ -0,0 +1,13 @@
+chgpasswd: the -c, -e, and -m flags are exclusive
+Usage: chgpasswd [options]
+
+Options:
+  -c, --crypt-method METHOD     the crypt method (one of NONE DES MD5 SHA256 SHA512)
+  -e, --encrypted               supplied passwords are encrypted
+  -h, --help                    display this help message and exit
+  -m, --md5                     encrypt the clear text password using
+                                the MD5 algorithm
+  -R, --root CHROOT_DIR         directory to chroot into
+  -s, --sha-rounds              number of SHA rounds for the SHA*
+                                crypt algorithms
+