- using `Object.create` for inheritance instead of creating a new instance of the base-class
- stop `initialize` from being reassigned to the same function on each prototype
Merge pull request #7 from FunkMonkey/refactor-inheritance

Use `Object.create` for prototypical inheritance
Viewer exporting tree with right order of children (see #6)
Merge branch 'master' of github.com:renatopp/behavior3js
fix merge