Issue#27: C interface implementation

following issue #27
Note this is not an optimal blueprint (headers sections are not where they should be).

A complex blueprint to test most of the interface wrappers would be:

```
FORMAT: 1A

# My API
Description of *My API*.

## Message [/message]
### GET
+ Response 200 (text/plain)

        Hello World!

# Group Red
Description of *Red* Group.

## My Resource [/myresource/{id}]
Description of *My Resource*

+ Model (application/json)
    + Headers

            X-Header: 1

    + Body

            { "message": "Hello World" }

    + Schema

            { "$schema": "http://json-schema.org/draft-03/schema" }

+ Parameters
    + id = `42` (number, optional, `1000`) ... Parameter `id` description.

### Retrieve My Resource [GET]
+ Response 200 (application/json)
    + Headers

            X-Header: 1

    + Body

            { "message": "Hello World" }

    + Schema

            { "$schema": "http://json-schema.org/draft-03/schema" }

### Create My Resource [POST]
+ Request (text/plain)

        Ni Hao!

+ Response 204
```