title: How to discover all Entity Types? One of each?
body: <p>I need to write a service that connects to CRM, and returns with a list of all of the entity available on the server (custom or otherwise).</p>
  
  <p>How can I do this?  To be clear, I am <em>not</em> looking to return all data for all entities.  Just a list of every type, regardless of whether any actually exist.</p>