Don't crash when Application.addPreferencesMenuItem() does not exist …

…on some newer OSX versions (#42)

org.alloytools.alloy.application/src/main/java/edu/mit/csail/sdg/alloy4whole/MacUtil.java

@@ -129,4 +129,21 @@ public void handleQuit(ApplicationEvent arg0) {
             }
         });
     }
+
+    /**
+     * Delegates the call to {@link #addMenus(SimpleGUI)} catching all errors. If no
+     * error is caught, <code>null</code> is returned; otherwise, the caught {@link Error}
+     * is returned.
+     *
+     * Use this method to guard from runtime exceptions thrown when running on newer versions
+     * of OSX that do not support adding OSX-specific menus from Java applications.
+     */
+    public Error tryAddMenus(SimpleGUI simpleGUI) {
+        try {
+            addMenus(simpleGUI);
+            return null;
+        } catch (Error e) {
+            return e;
+        }
+    }
 }

org.alloytools.alloy.application/src/main/java/edu/mit/csail/sdg/alloy4whole/SimpleGUI.java

@@ -1912,7 +1912,7 @@ private SimpleGUI(final String[] args) {
         }
         if (Util.onMac()) {
             macUtil = new MacUtil();
-            macUtil.addMenus(this);
+            macUtil.tryAddMenus(this);
         }
 
         doLookAndFeel();