Don't error if explanation has been given
Add explanation field to start page
Show error and explanation box if URL errors
Update explanation when an explanation is given
Rescue if ODIBot throws an error
Check response code rather than nil
Reuse explanation class from main survey
Styling
Support non-js users
Stub documentation_url_explanation
Hide popover after a few seconds
Remove debugger
Merge pull request #904 from theodi/bugfix-dont-error-when-explanation-given

Allow certificate to be completed if URL doesn't exist and explanation has been given.

Fixes: #843 and #882