[Enhance] PTT record & log DB cleaner

- Add support for recording users' potential each day
- Add a log database cleaner tool
- A small change: `/user/<user_id> PUT` API can ban user now.

latest version/core/user.py

@@ -763,7 +763,7 @@ class UserChanger(UserInfo, UserRegister):
         if columns is not None:
             d = {}
             for column in columns:
-                if column == 'password':
+                if column == 'password' and self.password != '':
                     d[column] = self.hash_pwd
                 else:
                     d[column] = self.__dict__[column]