Simplify and parallize test/automated Makefile

Simplify and parallize test/automated Makefile

* Makefile.in (mostlyclean, clean): Maybe clean test/automated.

* lisp/emacs-lisp/ert.el (ert-summarize-tests-batch-and-exit): New.

* test/automated/Makefile.in: Simplify and parallelize.
(XARGS_LIMIT, BYTE_COMPILE_EXTRA_FLAGS)
(setwins, compile-targets, compile-main, compile-clean): Remove.
(GREP_OPTIONS): Unexport.
(.el.elc): Replace with pattern rule.
(%.elc, %.log): New pattern rules.
(ELFILES, LOGFILES): New variables.
(check): Depend on LOGFILES.  Call ert-summarize-tests-batch-and-exit.
(clean, mostlyclean): New rules.
(bootstrap-clean): Simplify.
(bootstrap-clean, distclean): Depend on clean.

* .bzrignore: Ignore test/automated/*.log.

Fixes: debbugs:15991