Added a new verifications tab for credit invoices.
Added some guards. Added indentation of account rows. Added handling of tax return. All of it concerning finishing the current year.
Problem that updating of the customer list efter adding a new customer has been fixed.
Added quantity for generated events in order to maintain the stock properly. In addition made som clearifications.
Fixed bug that caused memory error when deleting verifications from business events.
Added quards to avoid memory error and reference mismash when editing or removing series.
Fixed bugs that computed depreciations incorrectly.
Added the possibility to re-open a closed year.