Add ability to define relationships in Schema differently when resource is main and included

[neomerx]

Relationship could be represented by all resource identities (type and id) in the relationship, or a link, or a combination of data, link and meta (real world example - paging (20 identities, links for more data and some meta with paging info)).
The lib currently supports all these combinations. Which is good. But I want moar 😄 I want to be able to

• include some resources + links + paging meta when resource is main
• keep only link to relationship data when resource is within included

something like this

{
    "data" : {
        "type" : "posts",
        "id"   : "1",
        "attributes" : {
            "..."
        },
        "relationships" : {
            "comments" : {
                "data" : [
                    { "type":"comments", "id":"5" }
                ],
                "links" : [
                    "<paging links for the rest of data here>"
                ],
                "meta" : {
                    "total-pages": "...",
                    "page-size": "..."
                }
            }
        }
    },
    "included" : [{
        "type"  : "comments",
        "id"    : "5",
        "attributes" : {
            "..."
        },
        "relationships" : {
            "replies" : {
                "links" : {
                    "self" : "<only link here, no identities when resource is included>"
                }
            }
        }
    }]
}

[neomerx]

Main change in Schema. Instead of

public function getRelationships($comment, array $includeList = []);

it should be declared as

public function getRelationships($comment, $isPrimary, array $includeList)

new parameter $isPrimary informs if $comment will be put into primary data section rather than included.