Update layout when camera window toolbar is hidden or shown

Although the actual visibility of the toolbars changes immediately, it seems
that WxWidgets doesn't automatically update the sizer layout afterwards, so
having hidden the toolbars we are left with just the grey background unless we
force a layout update manually.

radiant/camera/CamWnd.cpp

@@ -265,6 +265,10 @@ void CamWnd::updateToolbarVisibility()
 
     _mainWxWidget->FindWindow("CamToolbar")->Show(visible);
     _mainWxWidget->FindWindow("MiscToolbar")->Show(visible);
+
+    // WxWidgets/GTK doesn't seem to automatically refresh the layout when we
+    // hide/show the toolbars
+    _mainWxWidget->GetSizer()->Layout();
 }
 
 void CamWnd::onGLExtensionsInitialised()