Modularize Zetta

I broke out several modules.

* [zettajs/zetta-streams](https://github.com/zettajs/zetta-streams)
* [zettajs/zetta-device](https://github.com/zettajs/zetta-device)
* [zettajs/zetta-http-device](https://github.com/zettajs/zetta-http-device)
* [zettajs/zetta-scientist](https://github.com/zettajs/zetta-scientist)
* [zettajs/zetta-scout](https://github.com/zettajs/zetta-scout)
* [zettajs/zetta-auto-scout](https://github.com/zettajs/zetta-auto-scout)

Tests still need to be moved over to the new repos, but this was a pretty big effort.  I'm okay doing that later.