adderall.internal: Move reify from nested ifs to cond

cond is much easier to read, and compiles down to pretty much the same
functionality.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
adderall.internal: Simplify unify

Instead of an unmanageable mess of a nested if jungle, use cond for
unify too. Shorter, easier to understand.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
adderall.dsl: Add *s and *u

*s and *u are shortcuts for succeed and fail, respectively.

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