Revert "Remove the "quit" menu" because master branch must remain compatible with v1.2x

This reverts commit 645a3668e9.

config/menus.cfg

@@ -10,7 +10,7 @@ menuitem Demo         [ showmenu [Play demo] ]
 menuitem Editing      [ showmenu editing ]
 menuitem Help         [ showmenu help ]
 menuitem About        [ showmenu about ]
-menuitem "Quit AssaultCube"         quit
+menuitem Quit         savequit
 
 
 // Add maps to the below list to include them in the normal map menu (also for botmaps).
@@ -60,7 +60,7 @@ menuitem "Watch other demo" [ stopdemo; closecurmenu; showmenu [Play demo] ]
 menuitem "Search demo\i\3" [ showmenu [search demo] ]
 menuitem "" -1
 menuitem "\f4Main menu\i\3" [ closecurmenu; showmenu main ]
-menuitem "\f3Quit AssaultCube" quit
+menuitem "\f3Quit AssaultCube" savequit
 
 ////  Watching demo > rewind  ////
 
@@ -123,7 +123,7 @@ menuinit [
 ////  Main > About  ////
 
 newmenu about
-menuitem "AssaultCube Version 1.3" -1
+menuitem "AssaultCube Version 1.2" -1
 menuitem "" -1
 menuitem "AssaultCube is developed by various people around the" -1
 menuitem "world. People that enjoy making this game together." -1
@@ -137,6 +137,17 @@ menuitem "AssaultCube is a total-conversion of the CUBE engine" -1
 menuitem "by Wouter 'Aardappel' van Oortmerssen, and others:" -1
 menuitem "\t\f1http://www.cubeengine.com/" -1
 
+////  Main > Quit  ////
+
+newmenu quit
+menuitem "Yes, quit now" quit
+menuitem "No" [ showmenu [] ]
+menuitem "" -1
+menuitemcheckbox "Don't ask next time: " [(= $askquit 0)] [askquit = (= $arg1 0)]
+
+// Show quit dialog if enabled
+const savequit [ if $askquit [ showmenu quit ] quit ]
+
 
 // Create additional menus...
 exec config/menus_bot.cfg

config/menus_multiplayer.cfg

@@ -30,7 +30,7 @@ tempalias __ingamemenu_2 [
     menuitem "\f4Main menu\i\3"                   [ closecurmenu; showmenu main ]
     menuitem "\f4Browse servers\i\3"              [ closecurmenu; joinservermenu ]
     menuitem "\f3Disconnect from server"           disconnect
-    menuitem "\f3Quit AssaultCube"                 quit
+    menuitem "\f3Quit AssaultCube"                 savequit
 ]
 
 const __ingamemenu_showmodel [

config/menus_settings.cfg

@@ -497,6 +497,7 @@ looplist [
 ////  Main > Settings > Misc  ////
 
 newmenu Misc
+alias askquit 1
 alias showmenuonstartup 1
 alias menufilesort_cgz 0
 alias menufilesort_dmo 0
@@ -512,6 +513,7 @@ tempalias __getscreenshottype [
 menuitemcheckbox "Auto map download: " "$autogetmap"                 [ autogetmap $arg1 ]
 menuitem         "Configure auto media download \i\1"                 [ showmenu "Autodownload config"]
 menuitemradio "Show gamemode names " 0 1 "$modeacronyms" [ verbal abbreviated ] [ modeacronyms $arg1 ]
+menuitemcheckbox "Show quit dialog when quitting: " "$askquit"       [ askquit = $arg1 ]
 menuitemcheckbox "Show main menu when starting AC: " "$showmenuonstartup"   [ showmenuonstartup = $arg1 ]
 menuitemcheckbox "Auto-screenshot: " "$autoscreenshot"               [ autoscreenshot $arg1 ]
 menuitemcheckbox "Allow HUD echos: " "$allowhudechos"                [ allowhudechos $arg1 ]