URL values may be required to complete an upload in a single POST request,
which may include digest and size. This is not implemented in the server side,
yet, but is part of the HTTP API specification.
Routes and errors are now all referenced from a single v2 package. This
packages exports are acceptable for use in the server side as well as
integration into docker core.
To provide a single package with v2 API definitions, the locked down portions
of the API have been merged into a single package. References to exported items
will appear as v2.XXX, indicating their origin. The definitions in this package
will soon be locked down for change, acceppting only additions that will not
change protocol behavior.
