Key-management through command line

[goerz]

I would propose to add an ssh-keygen command to the blink> command line interface. There should also be commands for listing existing keys (so I can tell easily what names I can give to ssh-copy-id, and possibly a command to delete keys.

[goerz]

This would have the added benefit (assuming ssh-keygen is the same as the one that comes with OpenSSH), that it would create id_rsa by default, which would then be picked up automatically as the default key (see #51, #36)

[goerz]

An alternative to a utility for listing keys would be tab-completion of ssh-copy-id (see #43)

[carloscabanero]

Unfortunately I'm not sure I will have time to fit this before final release. But if someone considers it too important, please step in.

[carloscabanero]

The main proposal of this feature is already covered by the "keys" dialog. We will hopefully clear the default key management with #91. Please reopen if you think we can do better :)