Add repository URI view pages and IO/Display edit logic
- New View page for repository URIs.
- Make display and I/O behavior (observe, mirror, read, read/write) editable.
- Add a bunch of checks to prevent you from completely screwing up a repository by making it writable from a bunch of differnet sources.
Reviewed By: chad
Maniphest Tasks: T10748
Differential Revision: https://secure.phabricator.com/D15816