Activation

This release primarily provides support for relatively easy use of recyclable activation literals.

Additionally, we have renamed logic.Unroll to logic.Roll, which is shorter, and a noun, and
still makes sense.

Some incremental usage restrictions have been lifted. Namely, Test scopes can now
be used after an unsat query for subsequent queries (as would make sense for using
assumptions local to a test scope).

Some internals have been cleaned up.

No changes in performance are expected, as these implementations only trigger work local
to their use, which is only as of now available.

Enjoy.