support detachable menus in submenus of plugins menus user_shortcuts_init() and user_shortcuts_save() are moved to not the most convenient spot, as init has to happen after plugins init and before menus creation
git-svn-id: svn://svn.icculus.org/netradiant/trunk@1 61c419a2-8eb2-4b30-bcec-8cead039b335