Implementation and stability patches

This pull request contains:
 - Implementation for RopModifyRecipients request with partian x500dn
 - fixed use-after-free in EcDoRpcExt2 function
 - this commit allow for uses like:
   openchange_newuser --create --enable 'kcurtis'
 - check for return value for emsmdbp_object_open_folder_by_fid() in EcDoRpc_RopSyncImportHierarchyChange()
So, this patch has already been landed in.
Values 0 and 2 are for msExchUserAccountControl for the user.
I will propose separate patch for provision.accountcontrol() function