Running a subset of automated tests

[Barry OReilly]

Hi, I've found I want to run only one or a few of the tests at a time
rather than the whole suite. This patch would support:

  > make check EMACS_TESTS=cl-lib.el
  [...]
  Testing cl-lib.el
  [...]

  > make check EMACS_TESTS="*file*"
  [...]
  Testing file-notify-tests.el files.el
  [...]

Is it suitable to install? Note the patch is mixed with the patch in
bug 15170.

diff --git a/test/automated/Makefile.in b/test/automated/Makefile.in
index d4bfcc1..9d1e6c8 100644
--- a/test/automated/Makefile.in
+++ b/test/automated/Makefile.in
@@ -147,7 +148,7 @@ maintainer-clean: distclean bootstrap-clean
 
 check: compile-main
        @(cd $(test); $(setwins); \
-       pattern=`echo "$$wins " | sed -e 's|/\./|/|g' -e 's|/\. | |g' -e 's| |/*.el |g'`; \
+       pattern=$${EMACS_TESTS:=`echo "$$wins" | sed -e 's|/\./|/|g' -e 's|/\. | |g' -e 's| |/*.el |g'`}; \
        for el in $$pattern; do \
          test -f $$el || continue; \
          args="$$args -l $$el"; \