File owner/group API in new std::fs module

[jnicholls]

It appears as though the new std::fs module did not port over the abstraction of setting Ownership, like it did with setting Permissions. std::old_io::fs::chown is the only way to do this right now, particularly on a unix system.

Are we expected to FFI this ourselves at 1.0 beta/stable?

[alexcrichton]

Thanks for the issue! This is currently covered by rust-lang/rfcs#939 which is tracking a comprehensive look at the std::fs module to see how best to expand it in the future. Currently, yes, you'll need to call chown manually as we're not exporting a stable function for it.

[jnicholls]

Awesome, thanks for the link to the RFC (I need to get habitual about checking that first :)