Add Play button to map editor

mods/common/chrome/ingame-menu.yaml

@@ -2,7 +2,7 @@ Container@INGAME_MENU:
 	Width: WINDOW_RIGHT
 	Height: WINDOW_BOTTOM
 	Logic: IngameMenuLogic
-		Buttons: RESUME, LOAD_GAME, SAVE_GAME, SETTINGS, MUSIC, SURRENDER, RESTART, ABORT_MISSION, SAVE_MAP, EXIT_EDITOR
+		Buttons: RESUME, LOAD_GAME, SAVE_GAME, SETTINGS, MUSIC, SURRENDER, RESTART, ABORT_MISSION, SAVE_MAP, PLAY_MAP, EXIT_EDITOR
 		ButtonStride: 0, 40
 	Children:
 		Background@BORDER:

mods/common/languages/en.ftl

@@ -222,6 +222,12 @@ dialog-exit-map-editor =
     .confirm-anyway = Exit anyway
     .confirm = Exit
 
+dialog-play-map-warning =
+    .title = Warning
+    .prompt = The map may have been deleted or has
+    errors preventing it from being loaded.
+    .cancel = Okay
+
 ## IngamePowerBarLogic
 ## IngamePowerCounterLogic
 label-power-usage = Power Usage: { $usage }/{ $capacity }