Make site creation fail if the hostname is invalid

- In cases for example where it has a trailing slash.
- This uses URI.parse, which has to be given "http://" before the
  supplied hostname so that it works.
Merge pull request #633 from rjc123/newsites

Change date for MMO
Merge pull request #608 from alphagov/validate_hostnames

Make the `new_site` rake task fail if the hostname is invalid
[Civil Service] Update TNA timestamps

This is their final "full" crawl.
Merge pull request #634 from rjc123/newsites

Date changes for go-live
Add aliases for comare site