Merge branch 'js/valgrind'

Merge branch 'js/valgrind'

* js/valgrind:
  valgrind: do not require valgrind 3.4.0 or newer
  test-lib: avoid assuming that templates/ are in the GIT_EXEC_PATH
  Tests: let --valgrind imply --verbose and --tee
  Add a script to coalesce the valgrind outputs
  t/Makefile: provide a 'valgrind' target
  test-lib.sh: optionally output to test-results/$TEST.out, too
  Valgrind support: check for more than just programming errors
  valgrind: ignore ldso and more libz errors
  Add valgrind support in test scripts