Undo response-period id change
Merge pull request #1147 from alphagov/add-plugin-factory

Add plugin factory - plugins specific for each flow
Add two missing questions to the SPL flow
We were missing an additional question for mothers eligible for maternity allowance where we missing their 66-week salary on which the amount is based.
We were missing the amount of paternity leave planned by the mother's partner or principal adopter's partner for the paternity leave: choice between 1 or 2 weeks.
Fix compare task and remove common flase-errors

- Transition flows now have '-transition' appended, by convention,
  which means the flows don't share the same slug. Update the helper
  to be aware of this and pick the non-transition flow to compare
- Remove some false positive diffs:
  - Exclude sidebar, breadcrumb and analytics content from diff, as
    only the non-smartdown flow will have a real sluf, with related
    content for those areas
  - hide the '-transition' URL differences
Strip trailing new lines from yml-govspeak input

This was causing false-positives in the Smartdown transition
comparison tool, where YML content had (many) extra trailing
new lines.

They should be non-content affecting, so this won't
change any rendering behaviour, but will normalise the output
Upgrade Smartdown

This fixes a bug with previous question page titles and
removes some variable whitespace that was causing false
positives in the compare task
Fix off by one day bug for debit, credit, bacs and giro payments
Adjust tests to reflect new pay by dates
Merge pull request #1149 from alphagov/fix-smartdown-compare-task

Fix smartdown compare task
Merge pull request #1150 from alphagov/add-spl-questions

Add two missing questions to the SPL flow
Merge pull request #1151 from alphagov/fix-vat-payment-deadlines-bug

Fix vat payment deadlines bug
Implement SPL plugins