Finish to introduce `super_counter' that stress three different
implementation of `deep' with 1000 different invocations.
Add some "useful" comments about the design choice for the counter
signatures
Take counting signatures and functors apart, placing them in
their dedicated files under `mutable-storage' folder.
Refactor the counting code and put it in a dedicated folder.
Add the counting on `rember-one-star' function to show the magic
of `letcc' and `try'.
First attempt to study chapter 18 of Seasoned Schemer.
Implement a new version of `deep' with toppings remembering via letcc,
it doesn't work up to now.
Implement another version for `deep' with topping but it doesn't want to work.