Enable cumulativity for telescopes

This fixes iris#461 (closed) by enabling cumulative universe polymorphism in telescopes.v, allowing tele at a fixed universe (such as the Quant universe in iris) to cumulatively contain telescopes at smaller universes.

I also re-arranged existing telescope tests slightly in order to make sure the test for Unset Universe Minimization ToSet has a chance to fail before the accessor test, which happens to fail for the same reason.