title: get all implementations of an api
body: <p>I have written an API Bundle and some implementing services. </p>
  
  <p>Now i want to use them as plugins, so first of all i need a list of all the services i have.</p>
  
  <p>I'm starting the api like this: </p>
  
  <pre><code>    Framework m_fwk = new org.apache.felix.framework.FrameworkFactory().newFramework(null);
      m_fwk.init();
      AutoProcessor.process(null, m_fwk.getBundleContext());
      m_fwk.start();
  
      Bundle api = m_fwk.getBundleContext().installBundle(
      "file:/foo/bar/api/target/api-1.0.jar");
  
      api.start();
  </code></pre>
  
  <p>So now the API is loaded. Now i need to know which bundles implements this API, how can i get this information from the framework?</p>