For tax scales, always use "nb" attribute instead of "_nb" and compute "nb" directly from length.
Simplify TaxScale "option" handling.
Sort TaxScale methods.
Add missing initialization of variables.
Split TaxScale into several subclasses.
Remove obsolete "parameters" module.
Import module instead of its attributes.
Ensure that reforms are stored in Scenario instances instead of class.
Fix variable name
Rename constant_amount to amount.
Start working on structural reform