Arvados

The 'shared' directory uses full names. These have a couple of problems:

• Always contain spaces and may have other characters that make it awkward with Unix tooling
• Not unique. For example pirca has multiple accounts with full_name "Peter Amstutz". FUSE ends up picking one account and the other accounts just can't be accessed through FUSE.

It should use 'username' instead, which is unique on a given Arvados instance.

I think the only question is whether it is worth the effort to maintain backwards compatibility (by making the 'username' behavior a new option) or we just change the existing behavior in place.

I suppose one way to do it would be to change to using usernames by default but add an option that restores the previous behavior of using full names.