This commit consists of patches automatically generated for this project on https://scrutinizer-ci.com

missing import_key field, ref generator parameter must be task not
project, import must use css, serious database integrity problem
accepting duplicate tasks.

Uniformize code

enabled like for propal, order and invoice
The new event is linked to the project

In balance whole project, don't count the total amount in replaced invoices.
In invoice details the replaced invoices are OK.