Update Xcode project; fix Mac build.

Author: sa666666

src/emucore/Random.hxx

@@ -37,7 +37,7 @@ class Random : public Serializable
       Create a new random number generator with seed based on system time.
     */
     explicit Random() {
-      initSeed(std::chrono::system_clock::now().time_since_epoch().count());
+      initSeed(static_cast<uInt32>(std::chrono::system_clock::now().time_since_epoch().count()));
     }
 
     /**

src/gui/WhatsNewDialog.cxx

@@ -88,7 +88,7 @@ WhatsNewDialog::WhatsNewDialog(OSystem& osystem, DialogContainer& parent,
 
   // Set needed dimensions
   ypos += VGAP * 2 + buttonHeight + VBORDER;
-  assert(ypos <= FBMinimum::Height); // minimal launcher height
+  assert(ypos <= int(FBMinimum::Height)); // minimal launcher height
   setSize(MAX_CHARS * fontWidth + HBORDER * 2, ypos, max_w, max_h);
 
   WidgetArray wid;