clarify that the collection.href property value is not always the "self" URL

[mamund]

the URL in the collection.href property is not meant to represent the response URL. IOW, a Cj response from:

http://example.org/list/123 (showing a selected item)

will still have

collection.href="http://example.org/list/"

Note that is it fine to include a "self" link in the links collection, if desired.

This is a backward-compatible change for the format but it is possible some client libraries are not following this guidance. This should be discussed.

[sviox]

Having the collection.href point to collection instead of the requested item creates a situation where the client is unable to identify the requested item in case of an assorted collection using only mandatory, spec defined fields. Also, in many implementations the reference to parent collection might be something the service does not want to have due to access control on single item level.