To isolate check-parallel from traditional check, let's revert "setsid" and "privatens" test ways from check at first, due to "check" doesn't need them. This also helps to avoid some regression issues or behavior changes. The run_setsid and related things are removed totally, the privatens is removed from check too, but the run_privatens script is retained for check-parallel. Later, check-parallel will run in private name space way, won't affect the check running. More details refer to two patches. And please feel free to tell me if I miss something. Thanks, Zorro
