display "Recording state in git..." when staging the journal

A bit tricky to avoid printing it twice in a row when there are queued git
commands to run and journal to stage.

Added a generic way to run an action that may output multiple side
messages, with only the first displayed.

Annex/Queue.hs

@@ -26,15 +26,14 @@ add command params files = do
 flushWhenFull :: Annex ()
 flushWhenFull = do
 	q <- get
-	when (Git.Queue.full q) $ flush False
+	when (Git.Queue.full q) flush
 
 {- Runs (and empties) the queue. -}
-flush :: Bool -> Annex ()
-flush silent = do
+flush :: Annex ()
+flush = do
 	q <- get
 	unless (0 == Git.Queue.size q) $ do
-		unless silent $
-			showSideAction "Recording state in git"
+		showStoringStateAction
 		q' <- inRepo $ Git.Queue.flush q
 		store q'