We should allow Phurl URLs to be bound directly to objects instead of URLs. For example, you should be able to type `T123` instead of `http://whatever.com/` as the URL for a Phurl.
When a Phurl is bound to an object like `T123`, it can work a lot like it is bound to `http://whatever.install.com/T123`, but we can improve the behavior in some cases in the future. For example:
- Hovercards should show the target object;
- URLs bound to other URLs could redirect through a sequence of URLs, allowing you to alias `((problem))` and `((problems))` to the same place.
- Objects could show URLs that link to them.
To do this, we should probably:
- Add an objectPHID column.
- When a user sets a URL, check if it names an object. If it does, save an `objectPHID`. Otherwise, if it's a valid URL, save a URL. (Otherwise, error.)
- When a URL bound to an object is followed, load the object handle and redirect to `$handle->getURI()`.