CONN-218 New, simple maintenance script for checking founders

**DO NOT MERGE**

We'll merge this once the code and SQL queries are reviewed.

SQL query to review:
```sql
mysql> SELECT DISTINCT l.city_founding_user  FROM `city_list` `l` LEFT JOIN `user` `u` ON ((l.city_founding_user = u.user_id))  WHERE (l.city_founding_user <> 0) AND (l.city_founding_user IS NOT NULL) AND (u.user_id IS NULL) AND (l.city_created > '20140130000000');
+--------------------+
| city_founding_user |
+--------------------+
|            5438694 |
+--------------------+
1 row in set (0.00 sec)

mysql> explain SELECT DISTINCT l.city_founding_user  FROM `city_list` `l` LEFT JOIN `user` `u` ON ((l.city_founding_user = u.user_id))  WHERE (l.city_founding_user <> 0) AND (l.city_founding_user IS NOT NULL) AND (u.user_id IS NULL) AND (l.city_created > '20140130000000');
+----+-------------+-------+--------+-------------------------------------+--------------+---------+---------------------------------+------+------------------------------------------------+
| id | select_type | table | type   | possible_keys                       | key          | key_len | ref                             | rows | Extra                                          |
+----+-------------+-------+--------+-------------------------------------+--------------+---------+---------------------------------+------+------------------------------------------------+
|  1 | SIMPLE      | l     | range  | city_created,city_founding_user_inx | city_created | 9       | NULL                            |    1 | Using where; Using temporary                   |
|  1 | SIMPLE      | u     | eq_ref | PRIMARY                             | PRIMARY      | 4       | wikicities.l.city_founding_user |    1 | Using where; Using index; Not exists; Distinct |
+----+-------------+-------+--------+-------------------------------------+--------------+---------+---------------------------------+------+------------------------------------------------+
2 rows in set (0.01 sec)
```

I'm only not sure if I should use slaves for these selects. Is it better to use master in this case?

@SQLReview