get rid of implicitMessages state

Oh joyous day, this is probably git-annex's oldest implementation wart,
source of much unncessary bother.

Now that we have a StartMessage, showEndResult' can look at it to know
if it needs to display an end message or not.

This is also going to be faster, because it avoids an uncessary state
lookup for each file processed.

CmdLine.hs

@@ -122,10 +122,8 @@ findCmd fuzzyok argv cmds
 
 prepRunCommand :: Command -> GlobalSetter -> Annex ()
 prepRunCommand cmd globalconfig = do
-	when (cmdnomessages cmd) $ do
+	when (cmdnomessages cmd) $
 		Annex.setOutput QuietOutput
-		Annex.changeState $ \s -> s 
-			{ Annex.output = (Annex.output s) { implicitMessages = False } }
 	getParsed globalconfig
 	whenM (annexDebug <$> Annex.getGitConfig) $
 		liftIO enableDebugOutput