factory: add envs.common.ssh_args and envs.common.scp_args
tests: disable test_should_show_errors
factory: add ask_passwd boolean into envs.common, default is False
factory:
   refactoring operations:
      remove err_loop(),
      move capturing stderr to out_loop,
      refactor out_loop for writing unfinished messages into log,
      add secure request of password
factory:
  input arg for run() now can be a tuple of strings;
  add hack for windows into out_loop();
  change sudo to sudo -S;
  add description to run why it uses pipes when should pty