title: RxJS - observable doesn't complete when an error occurs
body: <p>When I create an observable from scratch, and have the observer error, then complete, the done part of the subscription never is invoked.</p>
  
  <pre><code>var observer = Rx.Observable.create(function(observer){
      observer.onError(new Error('no!'));
      observer.onCompleted();
  })
  
  observer.subscribe(
      function(x) { console.log('succeeded with ' + x ) },
      function(x) { console.log('errored with ' + x ) },
      function() { console.log('completed') }
  )
  </code></pre>
  
  <p>The output is:</p>
  
  <pre><code>errored with Error: no!
  </code></pre>
  
  <p>I'd expect it to be:</p>
  
  <pre><code>errored with Error: no!
  completed
  </code></pre>
  
  <p>If I change the code to invoke onNext instead of onError, the observable properly completes:</p>
  
  <pre><code>var observer = Rx.Observable.create(function(observer){
      observer.onNext('Hi!');
      observer.onCompleted();
  })
  
  observer.subscribe(
      function(x) { console.log('succeeded with ' + x ) },
      function(x) { console.log('errored with ' + x ) },
      function() { console.log('completed') }
  )
  </code></pre>
  
  <p>I get the expected output:</p>
  
  <pre><code>succeeded with Hi! 
  completed
  </code></pre>
  
  <p>Why does it not complete when an error has occured?</p>