title: Hibernate hbm2ddl.auto update does not drop columns with mysql
body: <p>Its adds new ones, but as far as I can see it does not drop the old ones ?</p>
  
  <p>When I say old ones, I mean properties of entity objects that are now completely removed,where previously they were present and annotated with <code>@column</code></p>
  
  <p>Are my only options to drop the col manually or change the config value to <code>create</code> ? Neither of which are particularly charming.</p>
  
  <p>Or something else ?</p>