[tor-dev] Alternative directory format for v3 client auth

[George Kadianakis]

Hello haxxpop and David,

here is a patch with an alternative directory format for v3 client auth
crypto key bookkeeping as discussed yesterday on IRC:
       https://github.com/torproject/torspec/pull/23

Thanks for making me edit the spec because it made me think of various
details that had to be thought of.

Let me know if you don't like it or if something is wrong.

Cheers!