Edit->Font->Bigger/Smaller validates properly

Fixes bug where the above items were enabled even when all windows were
minimized.

src/MacVim/MMAppController.h

@@ -34,8 +34,6 @@
 - (IBAction)fileOpen:(id)sender;
 - (IBAction)selectNextWindow:(id)sender;
 - (IBAction)selectPreviousWindow:(id)sender;
-- (IBAction)fontSizeUp:(id)sender;
-- (IBAction)fontSizeDown:(id)sender;
 - (IBAction)orderFrontPreferencePanel:(id)sender;
 - (IBAction)openWebsite:(id)sender;
 - (IBAction)showVimHelp:(id)sender;

src/MacVim/MMAppController.m

@@ -725,18 +725,6 @@ static int executeInLoginShell(NSString *path, NSArray *args);
     }
 }
 
-- (IBAction)fontSizeUp:(id)sender
-{
-    [[NSFontManager sharedFontManager] modifyFont:
-            [NSNumber numberWithInt:NSSizeUpFontAction]];
-}
-
-- (IBAction)fontSizeDown:(id)sender
-{
-    [[NSFontManager sharedFontManager] modifyFont:
-            [NSNumber numberWithInt:NSSizeDownFontAction]];
-}
-
 - (IBAction)orderFrontPreferencePanel:(id)sender
 {
     [[MMPreferenceController sharedPrefsWindowController] showWindow:self];

src/MacVim/MMWindowController.h

@@ -68,5 +68,7 @@
 - (IBAction)findNext:(id)sender;
 - (IBAction)findPrevious:(id)sender;
 - (IBAction)vimMenuItemAction:(id)sender;
+- (IBAction)fontSizeUp:(id)sender;
+- (IBAction)fontSizeDown:(id)sender;
 
 @end

src/MacVim/MMWindowController.m

@@ -609,6 +609,18 @@
     [vimController sendMessage:ExecuteMenuMsgID data:[attrs dictionaryAsData]];
 }
 
+- (IBAction)fontSizeUp:(id)sender
+{
+    [[NSFontManager sharedFontManager] modifyFont:
+            [NSNumber numberWithInt:NSSizeUpFontAction]];
+}
+
+- (IBAction)fontSizeDown:(id)sender
+{
+    [[NSFontManager sharedFontManager] modifyFont:
+            [NSNumber numberWithInt:NSSizeDownFontAction]];
+}
+
 - (BOOL)validateMenuItem:(NSMenuItem *)item
 {
     if ([item action] == @selector(vimMenuItemAction:)