Add [diff] mechanism

backend/store.py

@@ -12,6 +12,7 @@ class ChangeDetectionStore:
         self.needs_write = False
 
         self.__data = {
+            'note' : "Hello! If you change this file manually, please be sure to restart your changedetection.io instance!",
             'watching': {},
             'settings': {
                 'headers': {
@@ -126,7 +127,6 @@ class ChangeDetectionStore:
 
 
     def sync_to_json(self):
-        print ("Saving index....")
         with open('/datastore/url-watches.json', 'w') as json_file:
             json.dump(self.data, json_file, indent=4)
         self.needs_write = False