clean sigs

[Dirk Traulsen]

Hi!

I loaded a new key from a keyserver and cleaned it in the '--edit-
key' shell.
When I controlled the result with 'gpg --list-sigs 08B0A90B',
I found a lot of expired signatures. If you look at the output at 
sigs from the key CA57AD7C, you see that there are 7 valid newer 
signatures from this key and a lot of older expired signatures.
I thought, that these sigs should be deleted, if there is a newer 
valid signature from the same key.