Definitions: always include signature

[cgay]

When I write method signatures like this:

define method eval
    (ev :: <evaluator>, ast :: <expression>) => (value)

Using M-. on eval gives me this (not so useful):

and when I write the signature like this (all on one line):

define method eval (ev :: <evaluator>, ast :: <expression>) => (value)

I get a much more useful result:

We should always show the signatures, regardless of how they're written.