138217 r=cavin sr=bienvenu. Make folders of an acct in one profile do not show up for the same acct in another

profile in turbo mode. Clear the subfolders array when we are forcing shutdown of rootFolder and all its children.

mailnews/base/util/nsMsgFolder.cpp

@@ -287,6 +287,7 @@ NS_IMETHODIMP nsMsgFolder::Shutdown(PRBool shutdownChildren)
   // Reset incoming server pointer and pathname.
   mServer = nsnull;
   mPath = nsnull;
+  mSubFolders->Clear();  //clear mSubFolders array on shutdown, will come here if shutDownChildren is true
 	return NS_OK;
 }