Merge branch 'test-protocols' into testsuite-work

Merge branch 'test-protocols' into testsuite-work

* test-protocols:
  coverage: missing tap plan and non-zero exit status
  testsuite: fix an unportable use of sed
  testsuite: avoid spurious failure if rst2html program is missing
  fix: two recent ChangeLog entries
  tap: improve diagnosing and reporting of plan mismatches
  tap: log all TAP stream, even after a "Bail out!"
  coverage: TAP diagnostics after "Bail out!" aren't reported
  coverage: TAP errors after a "Bail out!" directive aren't reported
  testsuite: reorganize tests on TAP plans
  coverage: more TAP driver consistency w.r.t. 'prove'
  tap: improve some comments in the TAP driver
  tap: non-zero exit status after "Bail out!" should not be reported
  tap: a "plan with SKIP" after test results is an error
  test harness: avoid possible fork bomb
  coverage: possible infinite recursion in the test harness
  coverage: possible infinite recursion in the test harness
  test defs: yet more environment cleanup