Start building Monte-in-Monte language tests.

It doesn't quite work yet, though.
src/test: Test properties of bools.
Start testing lists.
Start building derp-style parser.
Add isInteger primitive and show off the int guard in Monte.

This is pretty cool!
Demonstration code for intervals.
More work on derp.
More derp.
Runtime type improvements and some serious derp.

Strange error that doesn't seem like miscompilation. Will investigate more
later.
Even more derp!
Derp to victory!
Make derp use the standard unittest module.
derp: Undo consing of lists in rep.
runtime/tables: Add a couple more methods to ConstList.
derp: Change alt() from taking a pair to taking a list of languages.

Allows expression of unlimited alternation, and the optimizations to
auto-prune dead branches are still present.