Hi,

This is to remove the ambiguity between 'delete' and 'delete-fork'
(by using the already-in-place mechanism that I should have used
in the first place).

I will still need to handle "detach-fork", which will probably
require making "detach" into a prefix command like "delete".
Thought I'd do that in a separate step.

I also elaborated the "info fork" command so that it could take
a fork id as argument -- mainly because it facilitates testing.

Michael