New gpg subkey

The GPG subkey I keep for daily use was going to expire, and this time I decided to create a new one instead of changing the expiration date.

Doing so I've found out that gnupg does not support importing just a private subkey for a key it already has (on IRC I've heard that there may be more informations on it on the gpg-users mailing list), so I've written a few notes on what I had to do on my website, so that I can remember them next year.

The short version is:

* Create your subkey (in the full keyring, the one with the private master key)
* export every subkey (including the expired ones, if you want to keep them available), but not the master key
* (copy the exported key from the offline computer to the online one)
* delete your private key from your regular use keyring
* import back the private keys you have exported before.