Saving, do not close the window…

Add the saving message.

_locales/en/messages.json

@@ -174,6 +174,16 @@
 	"settings_filters_target": {
 		"message": "Injection Target"
 	},
+	"saving_current": {
+		"message": "Saving…"
+	},
+	"saving_current_message": {
+		"message": "Leave your computer and this window open."
+	},
+	"saving_done": {
+		"message": "Saved!"
+	},
+	
 	"JSON_parse_error": {
 		"message": "There is a mistake in your JSON formatting. Please correct the error before saving."
 	},