Autofiller REST service

gistfile1.js

--> 
POST /tasks/autofiller/101

{
    object: {
        id: 101,
        description: 123,
        building: 234,
        site: 345,
        reporter: 456
    },
    changedFields: ["reporter"]
}

<-- 
200 OK

{
    object: {
        id: 101,
        description: 123,
        building: 678,
        site: 567,
        reporter: 456
    },
    changedFields: ["site", "building"]
}


To autofill an unsaved entity
=============================
POST /tasks/autofiller


PUT vs. POST
============
PUT is guaranteed idempotent, POST does not have to be. Our query is idempotent; 
in fact, it's nullipotent. So it could be PUT.

We are not replacing an existing resource or creating a new resource at the given 
URL. Suggests POST.
        
We are arguably creating a new query; the server will probably throw that away 
immediately after handling the request, but we can think of it that way. Suggests 
POST.