To use this module, you need to:

1.  Go to *Invoicing \> Customers \> Invoices*.
2.  Create a new sales invoice, choose a customer with a defined global
    discount and you will see how the value of the 'Invoice Global
    Discounts' field is auto-completed with the global discounts defined
    in the customer (See configuration section in this readme), although
    you can choose then other global discounts defined in configuration.
3.  Add several invoice lines.
4.  At the bottom of the form you will see how global discounts affect
    the total values.
5.  Go to the 'Journal Items' tab (if you have permissions for that).
    There you will see how the tax lines have the discount percentage
    applied and you will also see the lines that reflect the global
    discount applied.
6.  In the 'Other info' tab, you can see in the 'Global Discounts'
    table, the global discounts applied to each of the invoice lines.
