These were realy headaches but the testbenches are passing. We need to
take a look at the audio_buffer testbench for sure, it is way wrong and
needs reworked to use the interface. Should do a pass through every
module probably.
This module needs way reworked to just be a state machine. I was trying
to get way too tricky with it so I went back to the drawing board and
made a state machine diagram for it. The diagram is included with this
commit. I also moved the current collection of documentation to a doc/
folder, and added a second-long audio rom to test everything out once
the rom_sd is working.
