Adds enable, disable, confirm, sign-out, password reset and set-password
for one user; user group membership; group list, create and delete; and a
test sign-in that returns decoded token claims. A refused test sign-in is
an outcome rather than a 401, which would end the console session.
Also adds a generic GET for one flat item and a schema deleteImpact so
delete confirmations can say what else goes with a resource.
Zakaria