Add alias type Truth = Boolean Else Any

and TruthOps to test if isTrue or isFalse.
Add StringOps to basis.text

with show method to quote and escape strings.
Refine Else type and accompanying documentation

Rename the intentional Else type from Free to Bind. It was named Free
to evoke the idea of binding a free variable; also I did not want to
conflate it with the monadic bind operation–even though flatMap uses
it. But Bind sounds so much better, and the term Free has too many
overloads already (thanks Nora).

Lift Maybe to encompass all Trap types (type Maybe[+A] = A Else Any).
This also makes Truth equivalent to Maybe[Boolean].