Create or receive invoices as work is completed

This module is dual purpose; For the end user (Client) it allows contractors to generate an invoice once their work is completed which is available immediately for the clients accounts department. This improves cashflow for both the client and contractor. The sometimes long delays waiting for invoices to arrive are eliminated. For a contractor, as their employees log their hours and materials used, the invoice is automatically generated. It just remains for the admin to add hourly rates, markup, discount etc., and the invoice is available for their accounts department to transfer to their accounts software.