ChangeLog
- New persistent JSInterpreter object to avoid setup cost when reusing it
- Allow calling Python from JS through `call_python` function
- Allow using `evaljs` on file objects to run them
- Javascript exceptions now provide stactrace
- Support for `require()` to load modules in Javascript
- Built-in _JSX_ transpiler
- Working _react 0.14.8_ support
- Support for installing npmjs packages
- Fix memory leak