Account History Rating Diagrams; Item values can now be more than one character

The Value of an Account History Rating Diagram Item can now be more than one character.

Note, this does not mean the data stored in the database can have multiple characters per item.

What this allows you to do is convert an Item's value into another value on the fly. For example, you might store the number of days overdue in a month in a History Rating - but the number of days can range from 0 to 31. So, 10 to 31 are stored as A through U. When the Diagram is displayed you need to convert letters back into numbers.