Unify languages

I was wondering if it would be possible to replace the dynamic language with plain Carp.

AFAICS we could have something like a compilation cache to reduce the amount of compilation for dynamic functions and an execution cache to reduce the amount of "shelling out". With that in place, I guess it could be speedy enough. What do you think?

No files, tests, or entry points are named. Start by reviewing the issue discussion and the current dynamic-language implementation, then determine whether replacing it with plain Carp and adding compilation and execution caches is feasible; done means the language is unified without repeated compilation or shelling out.

Written by the indexing model from the issue text.