Add profile property

[DavidBiesack]

draft-kelly-json-hal-08 JSON HAL defines the optional string profile member which is not implemented in org.springframework.hateoas.Link. The profile field was requested in #656 but not implemented in 0.24.RELEASE. Please add it.

(As an aside, advice on how to extend the org.springframework.hateoas.Link class would be welcome. Lombok makes this pretty hard, since the @AllConstructor is package protected and not callable from the subclass. Without access to that super(...) constructor, I don't see a way to extend Link and add the field - there are no setters, only @Wither members which do not clone the subclass object but call a org.springframework.hateoas.Link1 constructor. Perhaps another enhancement would be to remove AccessLevel.PACKAGE )

[gregturn]

@DavidBiesack We don't wish to open up the visibility, so instead I've made an update to Link that I'll wait for @olivergierke to review and approve.

[DavidBiesack]

thanks for the PR to add profile. Since you have elected to not widen the scope of the constructor, is there some other way that one can subclass Link to add new fields?

[gregturn]

Link isn't reallly designed as an extension point to the project. In short you could fork and work from that.