This allows the golang ssh-agent to support the full suite of keys the library accepts. Currently constraints are ignored. Change-Id: I7d48c78e9a355582eb54788571a483a736c3d3ef Reviewed-on: https://go-review.googlesource.com/21536 Reviewed-by: Han-Wen Nienhuys <hanwen@google.com> Run-TryBot: Han-Wen Nienhuys <hanwen@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>