Escape works in quantity prompts

git-svn-id: http://svn.net-core.org/repos/t-engine4@663 51575b47-30f0-44d4-a5cc-537603b46e54

game/engine/dialogs/GetQuantity.lua

@@ -28,6 +28,9 @@ function _M:init(title, prompt, act)
 	self.act = act
 	self.qty = 0
 	self:keyCommands{
+		_ESCAPE = function()
+			game:unregisterDialog(self)
+		end,
 		_RETURN = function()
 			game:unregisterDialog(self)
 			act(self.qty)