macosx: update metadata in info panel if metadata changes

(cherry picked from commit 75fe831c3acc3c1066bacf30e846bb5e438fee31)

modules/gui/macosx/intf.m

@@ -1336,6 +1336,9 @@ static bool f_appExit = false;
 - (void)plItemUpdated
 {
     [o_mainwindow updateName];
+
+    if (o_info != NULL)
+        [o_info updateMetadata];
 }
 
 - (void)updateMainMenu

modules/gui/macosx/playlistinfo.h

@@ -113,6 +113,7 @@
 - (void)initMediaPanelStats;
 - (void)updatePanelWithItem:(input_item_t *)_p_item;
 - (void)setMeta: (char *)meta forLabel: (id)theItem;
+- (void)updateMetadata;
 - (void)updateStatistics;
 
 + (VLCInfo *)sharedInstance;

modules/gui/macosx/playlistinfo.m

@@ -179,6 +179,14 @@ static VLCInfo *_o_sharedInstance = nil;
 
 }
 
+- (void)updateMetadata
+{
+    if (!p_item)
+        return;
+
+    [self updatePanelWithItem:p_item];
+}
+
 - (void)updatePanelWithItem:(input_item_t *)_p_item;
 {
     NSAutoreleasePool *o_pool = [[NSAutoreleasePool alloc] init];