Account Processes; add scriptable CustomWhere option

A new scriptable "CustomWhere" parameter has been added to Account Processes.

This can be used in an "AccountProcesses" script to filter the list of Accounts to Process further, for example to eliminate Accounts that you don't want to process.

Note, all other filters will also be applied.

An script sample (snippet) is shown below:

' Handle Events
Select Case eventId
  Case "AccountProcessesPre"
    ' Account Processes is starting. Return False to abort

    AccountProcesses.CustomWhere = "Account.Ledger<>'Salvage'"
End Select