Enable `set -e' in more tests (plus some tweakings).

Enable `set -e' in more tests (plus some tweakings).

* tests/implicit.test: Enable `errexit' shell flag, and related
changes.  Add trailing `:' command.
* tests/insh2.test: Likewise.
* tests/instman2.test: Likewise.
* tests/interp.test: Likewise.
* tests/interp2.test: Likewise.
* tests/library.test: Likewise.
* tests/mclean.test: Likewise.
* tests/info.test: Enable `errexit' shell flag, and related
changes.  Add trailing `:' command.  Remove useless chaff from
generated Makefile.am.  Add a "FIXME" comment.
* tests/include.test: Enable `errexit' shell flag, and related
changes.  Add trailing `:' command.  Prefer cat + here-doc over
echo to append to configure.in.  Make tests more robust by using
longer and less common names to grep.  Remove an useless call to
echo.  Remove an useless subshell.
* tests/header.test: Enable `errexit' shell flag, and related
changes.  Use proper m4 quoting.  Add excerpts from the original
report of the bug tested for by this script.
* tests/gcj.test: Enable `errexit' shell flag, and related
changes.  Use proper m4 quoting.  Add trailing `:' command.
* tests/gcj3.test: Likewise.
* tests/ldflags.test: Likewise.
* tests/libtool.test: Likewise.
* tests/listval.test: Likewise.
* tests/javaprim.test: Likewise, and prefer cat + here-doc over
echo to append to configure.in.
* tests/javasubst.test: Likewise.
* tests/discorver.test: Enable `errexit' shell flag.  Prefer
trailing `:' over trailing `Exit 0'.
* tests/instdat.test: Enable `errexit' shell flag, and related
changes.  Use proper m4 quoting.  Avoid usless subshell.  Prefer
cat + here-doc over echo to append to configure.in.
* tests/libtool2.test: Enable `errexit' shell flag, and related
changes.  Add trailing `:' command.  Use the configure.in
stub provided by ./defs, rather than writing it from scratch.