Add special constructors for Organizations and Environments.  The Org constructor will go into a specified :initial-env and link it back to the org being constructed.  Also updated Uniqueable to update both names at the same time (the org's name, and the (-> org :initial-env :org :name).  Do a similar thing for Environments, where we link the environment to Library if no :prior is given.  Remove chained-env since the constructor makes it obsolete.  Update all references.