title: Spawning more threads than you have in a gevent pool
body: <p>As I understand it the idea of a pool in gevent is to limit the total number of concurrent requests at any time, to a database or an API or similar.</p>
  
  <p>Say I have code like this where I am spawning more greenlets than I have room for in the <code>Pool</code>:</p>
  
  <pre><code>import gevent.pool
  
  pool = gevent.pool.Pool(50)
  jobs = []
  for number in xrange(300):
      jobs.append(pool.spawn(do_something, number))
  
  total_result = [x.get() for x in jobs]
  </code></pre>
  
  <p>What is the actual behavior when trying to spawn the 51st request? When is the 51st request handled?</p>