Refactor fluxion.js
Refactor fluxion.js

- Remove setState() method
- Rename this._renderer as this.renderer
- Move loop() method into update() method (as a local function)
- Change inject() to return nothing
- Rename built-in events; now we have these:
  ':update-state'
  ':inject-state'
  ':start-async-update'
  ':end-async-update'

myoshida/fluxion