Assets: add removeLibrary() where unloading is optional (references #…

…1718)

unloadLibrary() now calls removeLibrary() with true for unload to prevent code duplication

src/lime/utils/Assets.hx

@@ -518,6 +518,11 @@ class Assets
 	}
 
 	public static function unloadLibrary(name:String):Void
+	{
+		removeLibrary(name, true);
+	}
+
+	public static function removeLibrary(name:String, unload:Bool = true):Void
 	{
 		#if (tools && !display)
 		if (name == null || name == "")
@@ -531,7 +536,10 @@ class Assets
 		{
 			cache.clear(name + ":");
 			library.onChange.remove(library_onChange);
-			library.unload();
+			if (unload)
+			{
+				library.unload();
+			}
 		}
 
 		libraries.remove(name);