A link has an optional name

The spec states:

>[5.5.  name](http://tools.ietf.org/html/draft-kelly-json-hal-05#section-5.5)
>
>   The "name" property is OPTIONAL.
>
>   Its value MAY be used as a secondary key for selecting Link Objects
>   which share the same relation type.

It's particularly useful when having handling arrays of Link Objects (see #9)