Modularize Arcanist settings, let users pick between ambiguous interpretations of arc browse ...
Summary:
Ref T10895. This modularizes Arcanist settings, but doesn't do anything with them yet.
When users type arc browse X, and only provide one "X", and there are several ways to interpret it, prompt them to choose one.
Test Plan: Created a file named T234, ran arc browse T234, was prompted to interpret it as an object or a path.
Reviewers: chad
Reviewed By: chad
Maniphest Tasks: T10895
Differential Revision: https://secure.phabricator.com/D16928