Invoice Transmit Method

This module adds a way to record, per contact, how invoices should be sent or received.

• On a customer record you can pick a "Customer Invoice Transmission Method"; on a vendor record you can pick a "Vendor Invoice Reception Method". Both are company-specific, so the same contact can have different methods in different companies.
• Three methods come ready to use: E-Mail, Post and Customer Portal. You can create more, and each method can be limited to customers, to vendors, or both.
• When you create a customer invoice or credit note, the transmission method is filled in automatically from the customer. For vendor bills and refunds it is taken from the vendor. You can still change it on the invoice.
• On customer invoices the method appears near the journal; on vendor bills it appears in a later tab.
• The "Send and Print" button is hidden unless the invoice's method is E-Mail or empty. So choosing Post or Customer Portal removes the send button; switching back to E-Mail brings it back.
• If a child contact is set to receive invoices by E-Mail, its email address becomes mandatory.
• A new "Transmit Methods" screen under Accounting configuration lets you manage the list, order it, archive entries, and search by name or code. Codes must be unique.

It touches account.move, res.partner and the new transmit.method model.