Update report a problem url on submit

Using pushState can change the url which a user encountered the error on.
Update the url just before form submission.
Merge pull request #436 from alphagov/update-url-report-problem

Update report a problem url on submit
Standardise table layouts

• update colour variables to use semantic variables
• update borders, padding and margins
• update font mixin to correct size

https://www.pivotaltracker.com/story/show/75347872
Not sure of the agile planner ticket number/URL
Merge pull request #437 from alphagov/standardise-tables-format

Standardise table layouts
User satisfaction markup injected by survey script

Previously, the markup was included in the base template all the time.
Apart from being an extra bit of markup in every request, this was also
causing issues with unusual clients, search spiders, etc.

This leaves only a wrapper with no content in the base template, and puts
the markup into the survey script. Since this script is going to be cached
by clients.
Add ari-hidden attributes to survey bar.
Merge pull request #438 from alphagov/include-survey-markup-with-script

User satisfaction markup injected by survey script