keymanager - use addresses instead of keys

I don't see why the user of the keymanager needs to handle keys, keymanager should know what key to use for you. In some cases keys need to be modified, for example to flag if the key is used, and if keymanager don't manage the keys this is more complicated.

New proposed API:

def encrypt(self, data, address, -pubkey,- passphrase=None, sign=None, cipher_algo='AES256', fetch_remote=True): def decrypt(self, data, address, -privkey,- passphrase=None, verify=None): def sign(self, data, address, -privkey,- digest_algo='SHA512', clearsign=False, detach=True, binary=False): def verify(self, data, address, -pubkey,- detached_sig=None, fetch_remote=True):

Need some research to see if that works for all our use cases right now.

Some debate about it: https://pad.riseup.net/p/keymanager-api

(from redmine: created on 2014-11-11, closed on 2015-01-07)