User Preferences; Added a new default setting for the Account Payment Arrangement wizard, Hold Overdue value

A new User Preference has been added to the Accounts, General page. Payment Arrangements 'Hold Overdue value'. The default is False.

This setting is used as the default value for the 'Hold Overdue value' checkbox on the Account Payment Arrangement wizard.

This setting has been added as some users will predominantly make Promises, so don't want to clear the Overdue balance and will likely forget to tick that box when making a new Promise.