Account Transaction table; added "ExtendedData" column

A new column "ExtendedData" has been added to the Account Transaction table.

This is a "memo" field that can store large amounts of text. It is designed to store additional custom information required by an individual site.

The following Business Layer functions can be used to save and retrieve this data:

finBatch.Transactions.ExtendedData to set the extended data in a Batch pre-commit script.

finAccountTransactionFunctions.UpdateExtendedData to update the extended data on an existing Account Transaction.

The finAccount object's Transactions collection, ie finAccountTransaction, now includes the additional property "ExtendedData" to view its current value.