title: Combine results of multiple ajax-requests
body: <p><br>
  in my webapp there are two types of entities, which are in relation to each other.
  At first i grab some entities of type a and then for every single one of them, i grab the related ones of type b as an array. All working.<br>
  When all requests are done, i need an array of all returned type-b-arrays. Not working!<br>
  Whats the best way to accomplish that in jquery ?</p>