ActiveSync synchronization overview
                     
                   
                
             
            
               
                  -  ActiveSync begins a synchronization session. 
- The ActiveSync provider sends a synchronize notification message to the first registered application on the device. The application
                     is started if it is not yet running. 
                  
- WndProc is invoked for each registered application. 
- Once the application has determined that this is the synchronize notification message from ActiveSync, the application calls
                     ULIsSynchronizeMessage to invoke the database synchronization procedure.
                  
- Once synchronization is complete, the application calls ULSignalSyncIsComplete to let the provider know that it has finished
                     synchronizing.
                  
-  Steps two-five are repeated for each application that has been registered with the provider.