Merge pull request #2450 from HyphaApp/feature/project-invoicing

hypha/apply/activity/messaging.py

hypha/apply/activity/migrations/0057_add_invoices.py

...a/apply/activity/migrations/0058_add_project_invoicing.py

hypha/apply/activity/options.py

...vity/templates/messages/email/invoice_status_updated.html

...ly/activity/templates/messages/email/invoice_updated.html

hypha/apply/projects/filters.py

hypha/apply/projects/forms/__init__.py

hypha/apply/projects/forms/payment.py

...a/apply/projects/migrations/0037_add_project_invoicing.py

hypha/apply/projects/models/__init__.py

hypha/apply/projects/models/payment.py

hypha/apply/projects/models/vendor.py

hypha/apply/projects/tables.py

...cts/templates/application_projects/includes/invoices.html

.../templates/application_projects/invoice_admin_detail.html

...emplates/application_projects/invoice_confirm_delete.html

...ojects/templates/application_projects/invoice_detail.html

...projects/templates/application_projects/invoice_form.html

...projects/templates/application_projects/invoice_list.html