Show error message when a dialog box can't be opened.

Rework defaults for ROM launcher and TIA zoom level.

Both of these are basically defined around having only a 640x480
screen, which hasn't been the case on hardware (even phones) for
about 10 years.

src/emucore/Settings.cxx

@@ -46,7 +46,7 @@ Settings::Settings(OSystem& osystem)
   setInternal("uimessages", "true");
 
   // TIA specific options
-  setInternal("tia.zoom", "2");
+  setInternal("tia.zoom", "3");
   setInternal("tia.inter", "false");
   setInternal("tia.aspectn", "90");
   setInternal("tia.aspectp", "100");
@@ -109,10 +109,10 @@ Settings::Settings(OSystem& osystem)
 
   // ROM browser options
   setInternal("exitlauncher", "false");
-  setInternal("launcherres", GUI::Size(640, 480));
+  setInternal("launcherres", GUI::Size(900, 600));
   setInternal("launcherfont", "medium");
   setInternal("launcherexts", "allroms");
-  setInternal("romviewer", "0");
+  setInternal("romviewer", "1");
   setInternal("lastrom", "");
 
   // UI-related options

src/gui/DialogContainer.cxx

@@ -19,6 +19,7 @@
 #include "Dialog.hxx"
 #include "Stack.hxx"
 #include "EventHandler.hxx"
+#include "FrameBuffer.hxx"
 #include "Joystick.hxx"
 #include "bspf.hxx"
 #include "DialogContainer.hxx"
@@ -114,6 +115,11 @@ void DialogContainer::draw(bool full)
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void DialogContainer::addDialog(Dialog* d)
 {
+  GUI::Rect r = myOSystem.frameBuffer().imageRect();
+  if(uInt32(d->getWidth()) > r.width() || uInt32(d->getHeight()) > r.height())
+    myOSystem.frameBuffer().showMessage(
+        "Unable to show dialog box; resize current window");
+  else
     myDialogStack.push(d);
 }
 

src/gui/Menu.cxx

@@ -21,8 +21,6 @@
 #include "bspf.hxx"
 #include "Menu.hxx"
 
-class Properties;
-
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 Menu::Menu(OSystem& osystem)
   : DialogContainer(osystem)