Defer game load to after UI initialization.

This removes both the double load that happens on startup and also
makes it possible to get the UI to create a new game if the existing
default.liberation is not compatible.

resources/stylesheets/style-dcs.css

@@ -19,6 +19,14 @@ grey text -------------------- #B7C0C6
 
 */
 
+/*
+ * Makes all message box text selectable.
+ * https://stackoverflow.com/a/32595502/632035
+ */
+QMessageBox {
+    messagebox-text-interaction-flags: 5;
+}
+
 /*QMenuBar*/
 QMenuBar {
     spacing: 2px; /* spacing between menu bar items */

resources/stylesheets/windows-style.css

@@ -1,3 +1,11 @@
 /*
 windows basis styles
 */
+
+/*
+ * Makes all message box text selectable.
+ * https://stackoverflow.com/a/32595502/632035
+ */
+QMessageBox {
+    messagebox-text-interaction-flags: 5;
+}