Includes Testing, Datastructures, Ansi Printer, and Pretty Printing, along with some basic core extras missing from the standard library.

The ansi printer and pretty printer were translated from Koka's Haskell compiler.

Some of this code is a stopgap measure until we have more efficient datastructures integrated into Koka. For example linearMap and linearSet are inefficient versions of map and set interfaces, but useful for building programs while we don't have official maps and sets.