Allow custom H1 and body for error pages
Store AKA hosts in the database

This means we will record hits against AKA hostnames when they appear in the
logs from our CDN.

This has made the `has_aka` field on Host and the code for finding aka hosts in
Transition::Import::DnsDetails confusing, hopefully I can simplify that...
Relate canonical and aka hosts

This allows us to simplify the Host model and the code for fetching DNS
details.
Add lib to autoload

This fixes an undefined constant Transition::OffSiteRedirectChecker in
MappingsController when bulk adding in development.
Make spec deterministic in the face of array order
Display dates in the local timezone

I noticed that times in the mapping history tab were displaying the time in UTC
rather than BST.
Always use Time.zone.now and similar

This is copied from imminence (and many of our other Rails apps), originally
copied from Whitehall.
Avoid time zone problems in DateTime

This is mostly hoop-jumping to make the check_for_bad_time_handling happy.

Date.current pays attention to the local time zone.

I think the old code would have generated a misleading count of days between
midnight and 1 AM.

This is also a touch simpler, which is nice.
Fix test broken by setting Rails' timezone
Helpful error on 404 from /mappings/find_global

Had to amend the test to decode the apostrophe which Rails made into an HTML
entity because it now considers the string to be not HTML-safe.
Record history when creating mappings from hits

This rake task is currently broken because the Mapping model validates that
a user is set to be recorded as the creator.
Merge pull request #241 from alphagov/record_history_for_creating_mappings_from_logs

Record history when creating mappings from hits
Merge pull request #240 from alphagov/use_correct_time_zone

Use correct time zone
Merge pull request #238 from alphagov/add_lib_to_autoload

Add lib to autoload
Merge pull request #231 from alphagov/helpful_404_on_find_global

Helpful 404 on find global
Merge pull request #236 from alphagov/store_aka_hosts_in_database

Store AKA hosts in database/Show AKA hits
Make MappingsFromHostPaths use #each for a large array

* Was using #map, which would allocate a large array we didn't use
Hotfix import:all:orgs_sites_hosts

* WhitehallOrgs had a reference to non-existent DateTime.zone introduced in #240
Merge pull request #242 from alphagov/mappings-from-host-paths-find-each

Make MappingsFromHostPaths use #each for a large array
Retrieve organisation_slugs from site YAML