GH-994 hopefully fix issue with people still using jar mods

Added an 'add mods' button to the version page
Add jar mods now has a very angry nag dialog until it's used successfully
Buttons on version page are rearranged to deemphasize jar mods

application/pages/BasePageContainer.h

@@ -0,0 +1,8 @@
+#pragma once
+
+class BasePageContainer
+{
+public:
+	virtual ~BasePageContainer(){};
+	virtual bool selectPage(QString pageId) = 0;
+};