Add autorelease pools to various info loading functions, so that adding massive amounts of tracks to the playlist will not run out of file handles.

Audio/AudioContainer.m

@@ -14,7 +14,9 @@
 
 + (NSArray *) urlsForContainerURL:(NSURL *)url
 {
-	return [[PluginController sharedPluginController] urlsForContainerURL:url];
+    @autoreleasepool {
+        return [[PluginController sharedPluginController] urlsForContainerURL:url];
+    }
 }
 
 @end

Audio/AudioMetadataReader.m

@@ -13,7 +13,9 @@
 
 + (NSDictionary *)metadataForURL:(NSURL *)url
 {
-	return [[PluginController sharedPluginController] metadataForURL:url];
+    @autoreleasepool {
+        return [[PluginController sharedPluginController] metadataForURL:url];
+    }
 }
 
 @end

Audio/AudioPropertiesReader.m

@@ -15,7 +15,9 @@
 
 + (NSDictionary *)propertiesForURL:(NSURL *)url
 {
-	return [[PluginController sharedPluginController] propertiesForURL:url];
+    @autoreleasepool {
+        return [[PluginController sharedPluginController] propertiesForURL:url];
+    }
 }
 
 @end