use printf %s instead of echo, as there are embedded \ chars in
some of the strings, and some other (nameless) shells insist on
treating \ in the args to echo as something special... (from kre@)
to the name of a shell, plus options that shell needs to run it
in the correct mode to be tested: eg: TEST_SH='bash -o posix'
Also finished the implementation of tests of "set -n" now that
the NetBSD shell supports that as it should. (from kre)
christos