Fix #update bug in DocumentMetadataDecorator

The extra attributes hash was completely replaced
on update with whatever was in the given hash.

This required the caller to provide all the
key/value pairs for the extra attributes or have
them wiped out. This was inconsistent with the
update behaviour of the other fields.
Merge pull request #175 from alphagov/fix-document-metadata-decorator

Fix #update bug in DocumentMetadataDecorator
Bump gds-sso to 9.3.0

Signon will start rejecting requests that don't include client_id in the
Near Future. Upgrading to 9.3.0 makes this app compatible before that
change happens.

This version of gds-sso has a dependency on multi_json 1.10.0, so bump
that too.
Merge pull request #176 from alphagov/bump-gds-sso

Bump gds-sso to 9.3.0
Use pluralised form for AAIB 'name'
Merge pull request #177 from alphagov/bug/correct-name-for-aaib-schema

Use pluralised form for AAIB 'name'
Fix bug where editing an invalid AAIB report 500'd

All pages which rerender a form need the model to be wrapped in a view
adapter, otherwise on validation failure we attempt to redisplay the
form, which then 500's.
Merge pull request #178 from alphagov/update-to-invalid-bugfix

Fix bug where editing an invalid AAIB report 500'd
Add required require to the wiring file

Add to_param method to attachment s.t. the rails helpers can pick up the
ID's correctly.
Merge pull request #179 from alphagov/add-require-to-wiring

Add required require to the wiring file
Reorder requires in wiring for clarity
Require ManualDocumentValidator in wiring
Require CmaCaseValidator in wiring
Merge pull request #180 from alphagov/bug/require-validator-in-wiring

Require MaunualDocumentValidator in wiring
Rename AttachmentsController to CmaCaseAttachmentsController
Rename AaibReportsAttachmentsController to be singular

This is the correct rails best practices
Rename ManualDocumentsAttachments to be singular

This is the rails best practices for controller naming conventions
Create and use AbstractAttachmentsController

This commit provides setup for making use of an abstract attachment controller which will provide common functionality to CmaCase and AaibReport attachments controllers
CmaCaseAttachment services to their own registry

In order to clean up the code and require different sets of services per controller, move the CmaCase related Attachment sevices to their own registry. We can now use a services method in the controller to decide which service registry to use
Correct spelling of registry