Test automake-generated portions of configure help screen.
* tests/help-depend.test: New test.
* tests/help-depend2.test: Likewise.
* tests/help-dmalloc.test: Likewise.
* tests/help-init.test: Likewise.
* tests/help-lispdir.test: Likewise.
* tests/help-maintainer.test: Likewise.
* tests/help-multilib.test: Likewise.
* tests/help-regex.test: Likewise.
* tests/help-silent.test: Likewise.
* tests/help-upc.test: Likewise.
* tests/mmode.test: Remove tests on `configure --help' output,
they are supersed by tests in `help-maintainer.test'.
* tests/Makefile.am (TESTS): Update.