Allow owners paths to be arbitrarily long and add storage for display paths
It adds pathDisplay to prepare for display paths and storage paths having different values. For now, pathDisplay is copied from path and always has the same value.
- Ran migration, checked database for sanity (all pathDisplay and path values identical).
- Added new paths, saw pathDisplay and path get the same values.
- Added an unreasonably enormous path with far more than 255 characters.
Maniphest Tasks: T11015
Differential Revision: https://secure.phabricator.com/D19183