outer tlog can jump by more than 1 after catchup
separated shaky tests into separate system_tests_long_shaky test suite (test_collapse, test_concurrent_collapse_fails, test_catchup_exercises, test_restart_master_long, test_243, test_272, test_inject_as_head)
Merge remote-tracking branch 'refs/remotes/origin/fix-test-243' into 1.6
Merge remote-tracking branch 'refs/remotes/origin/shaky-tests' into 1.6