adderall.dsl: Implement condⁱ properly

With the help of toolz, implement condⁱ properly, and enable a few tests
that were disabled before. This also drops eitherᵍ and Zzz, which are
not used anymore.

Signed-off-by: Gergely Nagy <algernon@balabit.hu>
adderall.dsl: Define monads earlier

Signed-off-by: Gergely Nagy <algernon@balabit.hu>
adderall.bitnum: Implement adderᵒ and gen-adderᵒ

The implementation is not fully correct yet, as adderᵒ does not use
allⁱ (because we don't have that yet), thus it does not always return
the expected solutions.

Signed-off-by: Gergely Nagy <algernon@balabit.hu>
tests: Add another adderᵒ test

Signed-off-by: Gergely Nagy <algernon@balabit.hu>
adderall.bitnum: Implement +ᵒ

Signed-off-by: Gergely Nagy <algernon@balabit.hu>
adderall.bitnum: Implement -ᵒ

Signed-off-by: Gergely Nagy <algernon@balabit.hu>