Sun Jun 10 14:50:05 EDT 2018

Trigger filter

Circuit is simple, but requires a lot of primitives that are not yet

- just did "concat"

- bit vector indexing

- equality

It makes sense to implement the shift register separately, and also
have a look at what the HDL output is for the MyHDL code.

EDIT: Create the primitives needed to build a shift register first.