title: DbContext and RejectChanges
body: <p>I was working with RIA services where ObjectContext has RejectChanges() method. However, I am now working with EF 4.4 in a desktop application and I cannot find that method. So, my question is: in a scenrario where I allow user to do batch CrUD operations on collection, how would I revert all the changes? I could go with recreating the Context and fetching the data again, but that sound highly unnecessary if I need to revert changes back to 1-2 entities.</p>
  
  <p>So, what is the best way to reject changes? And also, how do we know if the context is doing something (IsBusy)?</p>