Unable to issue subkey revocation

[marqueandreprisal at duck.com]

As I said yes I have done exactly this:
```
gpg --edit-key <key-id>
key 1
revkey
save
```
and is why I supposed a bug in gpg2. After doing so the key reports "no 
change". My guess of what the bug is would be when the primary key has 
been revoked gpg2 only assumes all subkeys are revoked while not actually 
applying subkey revocation packets.

To confirm this bug take a look at the key on 
keys.openpgp.org[https://keys.openpgp.org] and see if there are no 
revocation packets in the subkey.