Reporting; Ledgers range now displays a blank row allowing easy selection of Accounts that do not have a Ledger

The Ledgers range lookup used in reports now displays a blank row allowing easy selection of Accounts that do not have a Ledger.

This blank row will only display if there are Accounts in the database without a Ledger. When selected, the blank row will enter "<NULL>" into the range, thereby selecting Accounts without a Ledger.