[parrot/parrot] afffe0: Verify that at least 2 threads are created

[GitHub]

  Branch: refs/heads/threads
  Home:   https://github.com/parrot/parrot
  Commit: afffe06e14e284697a1edabca9241306d2c045bd
      https://github.com/parrot/parrot/commit/afffe06e14e284697a1edabca9241306d2c045bd
  Author: Reini Urban <rurban at cpanel.net>
  Date:   2012-09-16 (Sun, 16 Sep 2012)

  Changed paths:
    M src/thread.c

  Log Message:
  -----------
  Verify that at least 2 threads are created

For a single CPU default to 4 created threads.
For Parrot_set_num_threads verify at least 2, one is needed for sleep