Start work on a filter so we actually get stream of random binary out
Accidentally left a 'pass' in from earlier
Refactored a little bit so it's not so messy

Wasn't sure how to do it, I need a cache for the moving average and to
rewind it and take samples from the start of the stream but...

1. a class for the entire stream processor got too large too quick, was all
cruft and no code.

2. Globals are as taboo as gotos, so I avoided those.

3. A separate cache class ended up holding half of the state and made
all the token names all long and nasty.

So I've gone with a slightly messy Reader class which creates a sequence
generator on command, but keeps the average in itself.

Still doesn't feel right but my internet connection sucks
Fixed problem in previous commit

Yeah that should do it. The class is now an iterable!