Adds support for derivatives

Adds /derivatives to /resources/{resourceId}
Adds optional ?derivativeOf query parameter to POST /resources to automatically
link the new resource to the originating resource.
Adds examples for the new endpoints
derivatives response does not need parents
Adds examples for changes endpoint
Adds the changes endpoints
Derivatives example name scheme update
Fixes the resources example name scheme
Adds GUID to resource document

Fixes #1
Merge pull request #21 from abalmos/examples_fixup

Fix the resources examples naming scheme
Merge pull request #22 from abalmos/feature/derivative

Adds resource derivatives
Merge pull request #23 from abalmos/feature/guid

Add GUID to resources
Merge pull request #24 from abalmos/feature/changes

Add changes endpoint and resource changes endpoint

Conflicts:
	examples/resources/resources-id.get.json
	examples/resources/resources.expanded.get.json
	oada-api.raml
Update README.md

Fix link to `oada-api.raml`
Removing "access_token" query parameter.

OAuth token should only be provided via Authorization header.

Fixes #25
Merge pull request #26 from OADA/giri_oada_api_v1

Removing "access_token" query parameter.