Use of Retry-After HTTP header.
Allow passing the resource version number under 'resource' property.
Add 'Access origin' to the header.
Issue #180: Add access-callback per public field.
Try to decode JSON the request.
Abstract data providers, and add example.

Separated the RESTful handler from the underlying data provider (e.g. query builder). We now provide an EFQ data provider, and a DB data provider.
This opens the door for extending RESTful to act as a proxy to other providers (e.g. Solr, other web services, etc').

Also, added an example resource for the variables table, to show how to leverage the new data providers.
Merge pull request #193 from Gizra/decode-request

Try to decode JSON the request
Issue #194: Discovery for fields by @e0ipso, @nader77 and @amitaibu.
Issue #201: Refactor version negotiation.
Fix handling of 404.
Discovery endpoint by @amitaibu and @e0ipso.
Self url should point to the RESTful URL.
Document the discovery options.
Fix _links in pagination.
Show only latest resource by default in discovery.
Issue #218: Add header version in the response.
Merge pull request #218 from mateu-aguilo-bosch/218-header-version

Return resource version in the header
Avoid notices for missing plugnis upon clear cache.
Merge pull request #220 from Gizra/install-fixes

Avoid notices for missing plugins upon clear cache
Corrected the values given by angularFileUpload to drupal