Add an option to preload all banners. This adds to the screen load

time, but makes the actual screen much cleaner.

Add an option to disable banner preloading completely, to remove all
long waits completely.  Don't ChangeBannersWhenFast if we're set
to this.

stepmania/src/PrefsManager.h

@@ -56,7 +56,6 @@ public:
 	bool			m_bArcadeOptionsNavigation;
 	enum			{ NEVER, ALWAYS, ABC_ONLY } m_MusicWheelUsesSections;
 	int				m_iMusicWheelSwitchSpeed;
-	bool			m_bChangeBannersWhenFast;
 	bool			m_bEasterEggs;
 	bool			m_bMarvelousTiming;
 	int				m_iCoinMode;
@@ -89,6 +88,9 @@ public:
 	bool			m_bSoundPreloadAll;
 	bool			m_bAllowSoftwareRenderer;
 
+	enum BannerCacheType { preload_none, preload_all, preload_group };
+	BannerCacheType	m_BannerCacheType;
+
 	/* Game-specific prefs: */
 	CString			m_sDefaultNoteSkin;