Add refresh_seconds option for live image.

src/localize/languages/en.json

@@ -166,6 +166,10 @@
         "editor_label": "Live Controls"
       },
       "draggable": "Live cameras view can be dragged/swiped",
+      "image": {
+        "editor_label": "Live Image Options",
+        "refresh_seconds": "Number of seconds after which to refresh live image (0=never)"
+      },
       "layout": "Live Layout",
       "lazy_load": "Live cameras are lazily loaded",
       "lazy_unload": "Live cameras are lazily unloaded",