Remove examples. See https://github.com/nodyn/examples
Refactor of the runtime package, top level interfaces and Nodyn.

Nodyn is now an abstract class and does most of the work for a given
runtime - handling the event loop and application lifecycle. The runtime
implementation is responsible for the following:

    * Initializing the runtime with globals: `Nodyn#initialize()`
    * Compiling scripts: `Nodyn#compile(String, String, boolean)`
    * Running scripts: `Nodyn#runScript(String)`
    * Loading 'native' bindings: `Nodyn#loadBinding(String)`
    * Handling exceptions: `Nodyn#handleThrowable(Throwable)`

Runtime implementations are required now to provide a factory class that
implements RuntimeFactory. The factory is responsible for creating
instances of `Runtime` and `Config`.

Added a stubbed implementation for Nashorn that is not enabled (or even
functional) yet.
Add missing copyright on new classes
Remove dynjs references from contextify.js.

To do this, two abstract methods have been added to Nodyn.java:
Nodyn#makeContext(Object) and Nodyn#isContext(Object).
Broken checkpoint