=== POST to the set to create a Track to edit (on an existing CD)
Request:
POST /track?prefetch=self
Accept: application/hal+json
{ "title":"Just One More", "position":4200, "cd":2 }
Response:
201 Created
Content-type: application/hal+json
Location: /track/19
{
   "_links" : {
      "cd" : {
         "href" : "/cd/2"
      },
      "cd_cref_cond" : {
         "href" : "/cd/2"
      },
      "cd_single" : {
         "href" : "/cd/19"
      },
      "disc" : {
         "href" : "/cd/2"
      },
      "self" : {
         "href" : "/track/19"
      }
   },
   "cd" : 2,
   "last_updated_at" : null,
   "last_updated_on" : null,
   "position" : 4200,
   "title" : "Just One More",
   "trackid" : 19
}

=== update the title (19 hardwired for now) and prefetch self and disc
Request:
PUT /track/19?prefetch=self,disc
Accept: application/hal+json
{ "title":"Just One More (remix)" }
Response:
200 OK
Content-type: application/hal+json
{
   "_embedded" : {
      "disc" : {
         "artist" : 1,
         "cdid" : 2,
         "genreid" : 2,
         "single_track" : null,
         "title" : "Forkful of bees",
         "year" : "2001"
      }
   },
   "_links" : {
      "cd" : {
         "href" : "/cd/2"
      },
      "cd_cref_cond" : {
         "href" : "/cd/2"
      },
      "cd_single" : {
         "href" : "/cd/19"
      },
      "disc" : {
         "href" : "/cd/2"
      },
      "self" : {
         "href" : "/track/19"
      }
   },
   "cd" : 2,
   "last_updated_at" : null,
   "last_updated_on" : null,
   "position" : 4200,
   "title" : "Just One More (remix)",
   "trackid" : 19
}

=== update the track id (primary key)
Request:
PUT /track/19?prefetch=self
Accept: application/hal+json
{ "trackid":1900 }
Response:
200 OK
Content-type: application/hal+json
{
   "_links" : {
      "cd" : {
         "href" : "/cd/2"
      },
      "cd_cref_cond" : {
         "href" : "/cd/2"
      },
      "cd_single" : {
         "href" : "/cd/1900"
      },
      "disc" : {
         "href" : "/cd/2"
      },
      "self" : {
         "href" : "/track/1900"
      }
   },
   "cd" : 2,
   "last_updated_at" : null,
   "last_updated_on" : null,
   "position" : 4200,
   "title" : "Just One More (remix)",
   "trackid" : 1900
}

=== delete the track we just added
Request:
DELETE /track/1900
Accept: application/hal+json
Response:
204 No Content
Content-type: application/hal+json