add preferred stamp duty url routes
let superclass handle params to choose tool name
hard code affordability tool name
Merge pull request #119 from moneyadviceservice/urls

Step towards better urls
remove pence from page 2 input fields
refactor affordability form to follow same structure as the other calculators
remove fieldset elements
extract out legend elements
use verbose conditional to split inputs so required layout can be achieved, not elegant but a temporary solution until we can find a better way to do this
another verbose conditional to seperate person 1 and 2 extra income fields
comment temporary clear fix to align layouts
extract step sections into partials
Merge branch 'affordability-inputs' of github.com:moneyadviceservice/mortgage_calculator into affordability-inputs

rebasing