A set of utility functions for Python that the Commonsense Computing project uses in multiple projects.

Includes:

* A `foreach` with progress reporting (also Status.reporter)
* A generator for the "sampling sequence" (binary van der Corput sequence),
  useful for incremental resolution on graphs.
* A dictionary that stores its items as pickles in a directory. Features
  lazy loading and lazy evaluation.

Plus a few more odds and ends.