Comment 2 for bug 1839341

I've squashed down my commits and the above-linked branch contains the latest code. This should resolve bug 1450519 for the Angular UI - it includes a new API call, open-ils.actor.org_unit.settings.history.retrieve, which retrieves the history of an Org Unit Setting in a way that accounts for permissions. It also utilizes a feature added by Bill Erickson in bug 1850555 to cover situations where an Org Unit Setting Type refers to a Shelving Location.