0 as a parameter

[danipoal]

When a 0 is found as a parameter, it stops printing the next va_list arguments.

[danipoal]

1 - When va_copy is done, we use the cpy parameter and we dont use the original, then this one is never poped out of the list.
2 - The returned bytes are wrong when a NULL is found.

[danipoal]

Error si pones % al final, ya que da overlflow.

Error si lo tengo % y hay un arg null, lo consumira igualmente