update the cli to support variable-width object IDs
update the cli to support variable-width object IDs

Summary:
EdenFS no longer uses 20-byte binary commit hashes and object
IDs. Instead, they're variable-width, and returned over Thrift in a
semi-human-readable format. Update the CLI to render them in a
reasonable way.

Reviewed By: kmancini

Differential Revision: D34573818

fbshipit-source-id: 11e987093db08ddae79e728435031230f5f2783e

facebook/watchman,facebook/watchman,facebook/watchman,facebook/watchman,facebook/watchman,nodakai/watchman,facebook/watchman,nodakai/watchman,nodakai/watchman,facebook/watchman,nodakai/watchman,nodakai/watchman,nodakai/watchman,nodakai/watchman,facebook/watchman,nodakai/watchman,facebook/watchman,nodakai/watchman