title: Clean (remove) a database in MagicalRecord
body: <p>I have an app that is using MagicalRecord for its Core Data handling and this works nice. However I have different users that can login in the app and when another user logs in, the core data database must be emptied so that the different user can have his own data. The database can be emptied completely as the data is also stored on a webservice and therefore can always be synced again after logging in again the first user.</p>
  
  <p>So far I cannot seem to find a helper method (that works) for this purpose. I have tried</p>
  
  <pre><code>[MagicalRecord cleanUp];
  </code></pre>
  
  <p>whenever the user is logging out, but this does not do the trick.</p>