Use specific media type for the W3C API

[vivienlacourba]

Following discussions started with @tripu on issue #29 I went to the conclusion that it will make things easier if the W3C API had its own media type. That way we could clearly identify when link relations points to another W3C API resource (using the type property on link objects).

@dontcallmedom also suggested we include the API version in the media type as done by GitHub.

FYI, several popular APIs are using their own media type:

• SensioLabs (Symfony): application/vnd.com.sensiolabs.connect+xml
• GitHub: application/vnd.github.v3+json

Proposed W3C API media type: application/vnd.org.w3.api.v1+json

Explanation:

• vnd indicates it is a vendor-specific MIME type
• org.w3.api indicates it's the W3C API
• v1 version 1.x of the API we would change the major version number only when we bring changes that break backward compatibility
• Adding hal might be an overkill and would only be a human readable hint to indicates we follow HAL (the only official HAL media type being application/hal+json)
• +json to says we follow the "application/json"
  sends back JSON objects (+json)

[vivienlacourba]

Issue description updated as I actually forgot the version number, and also after some thought having hal in the media type seemed like an overkill, it would have been either:

• application/vnd.org.w3.api.v1.hal+json
• application/vnd.org.w3.api.hal.v1+json

[vivienlacourba]

For future thoughts the JSON-LD media type is application/ld+json.

[akuckartz]

Please do not create YAMT (Yet Another Media Type). Use application/ld+json. Thanks.

[tripu]

👍 to reuse an existing media type (application/hal+json).

[tripu]

FWIW, my two API clients don't need this any more; cf #29 (comment).