Merge pull request #69 from alphagov/move_whitelist_to_db

Use the database for the new URL whitelist
Use the new Site.global_type column

...instead of global_http_status. This also includes Transition's
current db/structure.sql, which has some bits of accidentally-committed
collation diff, but since that should be sorted out in transition first
I've copied it all over as-is.
Merge pull request #76 from alphagov/use_site_global_type

Use the new Site.global_type column
Treat unresolved mappings as archived

* No decision has been made
* Rack returns a 410
Merge pull request #77 from alphagov/unresolved-defaults-to-archive

Treat unresolved mappings as archived
Add rules to serve devolved businesslink content

This commit attempts to replicate rules behaviour for NI and Wales devolved www.businesslink.gov.uk sites, as initially implemented here https://github.com/alphagov/redirector/blob/master/configs/businesslink.conf#L36

Using a rule here rather than a mapping allows us to avoid adding 'site' as a significant query string parameter, and having to guess / regenerate / recanonicalise all the businesslink mappings to work (for many other URLS, other site numbers and conflating other rules / piplinks / etc)
Refactor pre-emptive rules to be case-based