Michel catalog numbers should support letters

[php-coder]

Similar to #671 but for Michel catalog. We need to support letters in catalog numbers. For example: Mi#1140-43B Bl#63B

[php-coder]

I can't add it manually:

mysql> insert into michel_catalog(code) values('1140B');
ERROR 1406 (22001): Data too long for column 'code' at row 1
mysql> desc michel_catalog;
+-------+------------+------+-----+---------+----------------+
| Field | Type       | Null | Key | Default | Extra          |
+-------+------------+------+-----+---------+----------------+
| id    | int(11)    | NO   | PRI | NULL    | auto_increment |
| code  | varchar(4) | NO   | UNI | NULL    |                |
+-------+------------+------+-----+---------+----------------+

[php-coder]

I can't add it manually:

This is similar to #676 when we increased the length of scott_catalog.code field to 5 characters.

[php-coder]

We need the same for Yvert: 1100A-1104A