Sat May 26 11:29:01 EDT 2018

Export a module

Because we only do sequential logic, it is essential that we are able
to export standard (MyHDL) modules that can be included in a
simulation that also handles asynchronous logic.

The basic idea is that:

- async logic is sometimes necessary for interfacing, but is too
  low-level to be used for the bulk of a circuit

- syncrhonous logic is simpler, and this simplicity can be used to
  express it in a simpler language