Business Layer; ISKeyValueListRO.GetDouble now supports an option to return Nan as zero

The ISKeyValueListRO Business Layer object's "GetDouble" function now supports an option to return Nan (Not a Number) as zero. Compare this to ISKeyValueList, which had already implemented this option.

The function's signature is now GetDouble(key As String, Optional defaultValue As Double = 0, Optional returnNanAsZero As Boolean = False).

This makes it easier to handle Double type variables where "Nan" is a possible value stored in a key/ value pair.

Note, various functionality use ISKeyValueLists behind the scenes. For example, UserData is stored as an ISKeyValueList. In a global collection, such as Departments, UserData is exposed as a ISKeyValueListRO object as the object is Read-Only.