Initialize layout:

- create nav_bar, nav_side, and flash_messages partials
- add layout locales
- move assets gems out of assets group
Create VatRate :

- create vat_rates table
- add seeds
- create model, decorator
- create parameters namespace
- create parameters/vat_rates resources
Create CostDefinition :

- create table, model, decorator
- add parameters/cost_definitions resources, controller and views
Create Cost :

- create table, model, decorator
- add parameters/costs resources, controller and views