Getting closer to v1.0

Biggest changes:

• dropped the object interface for a functional one
  • yield disappears. The machine is now just a stateful function
• machine now takes a configurable initial control state
• testing utilities are separated into their own package : state-transducer-testing
• helper function to make web component from a machine
  • only use lightly custom elements v1, and not shadow DOM in order to limit polyfill for older browsers

Also miscellaneous bug fixes.