Don't show the warning on ScreenMapControllers if the dismiss time is too short to read it.

Docs/Changelog_sm5.txt

@@ -4,6 +4,14 @@ The StepMania 5 Changelog covers all post-sm-ssc changes. For a list of changes
 from StepMania 4 alpha 5 to sm-ssc v1.2.5, see Changelog_sm-ssc.txt.
 ________________________________________________________________________________
 
+2015/07/11
+----------
+* [ScreenMapControllers] If the AutoDismissWarningSecs metric is less than
+  .25 seconds, the warning will not be shown (the TweenOn command for it will
+  not be played).  Instead, the NeverShow command will be played.  If the
+  NeverShow command does not exist for the warning actor, the warning actor
+  will be set to hibernate forever. [kyzentun]
+
 2015/07/02
 ----------
 * [Gameplay] Random background video behavior is now controlled by these

src/ScreenMapControllers.cpp

@@ -227,7 +227,21 @@ void ScreenMapControllers::BeginScreen()
 	m_AutoDismissWarningSecs= THEME->GetMetricF(m_sName, "AutoDismissWarningSecs");
 	m_AutoDismissNoSetListPromptSecs= 0.0f;
 	m_AutoDismissSanitySecs= 0.0f;
-	m_Warning->PlayCommand("TweenOn");
+	if(m_AutoDismissWarningSecs > 0.25)
+	{
+		m_Warning->PlayCommand("TweenOn");
+	}
+	else
+	{
+		if(m_Warning->HasCommand("NeverShow"))
+		{
+			m_Warning->PlayCommand("NeverShow");
+		}
+		else
+		{
+			m_Warning->SetHibernate(16777216.0f);
+		}
+	}
 }