adderall.internal: reify all sequable datatypes

Instead of reifying only tuples, reify all seqable datatypes, so that we
can use lists and vectors too.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
tests: Convert the Reasoned Schemer chapter #1 tests to cons

Now that we can correctly reify lists too, introduce (lcons) for the
sake of the test (within the test case), and use it instead of tuples.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>