Re-added "Don't stretch/shrink" option

Closes #345

modules/client_options/graphics.otui

@@ -39,6 +39,10 @@ Panel
     id: fullscreen
     !text: tr('Fullscreen')
     tooltip: Ctrl+Shift+F
+    
+  OptionCheckBox
+    id: dontStretchShrink
+    !text: tr('Don\'t stretch/shrink Game Window')  
 
   Label
     id: backgroundFrameRateLabel
@@ -46,7 +50,7 @@ Panel
     anchors.left: parent.left
     anchors.right: parent.right
     anchors.top: prev.bottom
-    margin-top: 6
+    margin-top: 12
     @onSetup: |
       local value = modules.client_options.getOption('backgroundFrameRate')
       local text = value