[6.0.1 & 5.0.15] Wishlist - account_analytic_analysis: last invoice date should include manual invoices

[Bernard Renier - ADN]

Hello,

For the moment, there is an issue on last_invoice_date field on account_analytic_analysis. It reads only invoices generated by automatic billing from analytic account, but it does not read any of the manual invoices.

I think this change will be very useful as many service companies are not always using automatic billing, but are using manual invoices:
- no pure time & materials contracts, so you can't charge all of the costs automatically
- when using several accounts for the different phases on a huge project, they want to be able to provide periodically invoices on all phases in one invoice document (using the automatic billing generates one invoice per analytic account).

The field last_invoice_date is fundamental for a project manager, because he can see quickly if the project has been invoiced for a while or not.

This wishlist item follows bug 711737 - https://bugs.launchpad.net/openobject-addons/+bug/711737 - where it was agreed to change the help text to mention that the field reads only automatic invoices.

To fix definetly this issue about manual invoices, two ways are possible:
- Modifying the code behind the existing last_invoice_date (bug 711737 explains two code modification options)
- Adding an additional field last_invoice_date_manual that will show the last manual invoice date.

Regards,

Bernard