General Ledger Export; updated tooltips

Tooltips in the General Ledger Export wizard have been updated as follows:

• Account Ledger Date To tooltip removed.
• This referred to redating transactions as per the Date Closed To
• Date Closed toolltip now reads "All Transactions dated on or before this date will be re-dated to the day after this date. This prevents transactions being created for a closed off Accounting Period."
• This makes it more explicit on how the dates are applied.