Move `lastAction` out of status doc

[richard-jones]

lastAction is uncomfortable in the Status Doc, and would be better if it wasn't there. Instead, the proposal is: for any POST to an operation that is not to the Object-URL, we SHOULD NOT return the Status Doc (it's not RESTful to do so), instead we should return a "Last Action Doc" (which doesn't yet exist in the spec) + a Location header when the deposit operation warrants it.

The Last Action doc should contain all the data that's currently in the lastAction section of the Status Doc, and it should also be possible to include the locations of any created resources, where there are multiple resources involved. For example, deposit of multiple files By-Reference cannot return a single Location, so it should return a Last Action Doc, which lists all the files that were deposited. Exact form of this extension TBD.

[richard-jones]

After consideration, the way to move forward here is simply to remove lastAction from the Status Doc and specification as a whole. It isn't particularly useful in its current form, as noted, as the Status Doc is not returned after every request. Requiring each request to start presenting a "Last Action" document places extra burden on the client, for limited additional value. The client knows what it did, and if it wants to see the state of the object, then it can GET on the Object-URL.

Actions therefore are:

• Remove lastAction from the Status Doc

In the process of making this decision, a Last Action document type was drafted, and this will be left in the code repository for future reference but not promoted to the specification itself.