Merge branch 'maint'

* maint:
  tests: don't trust the exit status of "make -k" for non-GNU makes
  parallel-tests: reimplement fix for bug#11791
  tests setup: unset CDPATH
  tests setup: more namespace safeness
  tests setup: remove an unused variable
  tests setup: less hard-coding of the test subdirectory

diff --cc lib/am/check.am
Simple merge

diff --cc t/ax/test-init.sh
Simple merge