This changeset provides a common http handler for serving errcodes. This should
unify http responses across webservices in the face of errors.
Several type assertions have been added, as well, to ensure the error interface
is implemented.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
The goal is to free up the distribution/registry package to include common
registry types. This moves the webapp definitions out of the way to allow for
this change in the future.
Signed-off-by: Stephen J Day <stephen.day@docker.com>