crypto/tls: Conn.Close returns non-nil error

[adg]

When closing a connection, the error "local error: close notify" is returned
on success.

This behaviour should either be documented, or the Close method should return nil for
this specific case.

[agl]

Comment 1:

http://golang.org/cl/2107048/

Status changed to Started.

[agl]

Comment 2:

This issue was closed by revision 5011c27.

Status changed to Fixed.