Refactor everything, separate modules, make it simple

- Improve initializers (and middleware, etc) #228 

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- [x] asimov-test
- [x] asimov - only cli command loader, main public interface for sequence loader
- [x] specs for asimov.js sequence loading
- [ ] port pages stuff to asimov-pages
- [ ] port server stuff to asimov-server
- [ ] move modules to own repos and publish to npm