* lib/am/libs.am (ARFLAGS): Define.

* lib/am/libs.am (ARFLAGS): Define.
* automake.in (handle_libraries): Use `$(ARFLAGS)' instead of
hard-coding `cru'.
* automake.texi (A Library): Explain how AR, ARFLAGS and RANLIB
are used, and how they can be overridden.
(Program and Library Variables): Adjust to show `$(ARFLAGS)'
instead of `cru'
* tests/ar.test: Rewrite to test for AR, ARFLAGS, and RANLIB.
* tests/ranlib.test: Delete, obsoleted by ar.test.
* tests/Makefile.am (TESTS): Remove ranlib.test.
Report from Paul Thomas.