Adding test harness to current implementation

[hath995]

To run the tests:
npm install -g mocha
npm install chai

mocha tests/

[hath995]

Just to be clear with the current implementation of try/catch/finally. The following tests fail:

1. Should handle the exception in the outer try catch exception, and finish inner finally
2. Should handle rethrowing the error, and catching in the outer (infinite loop)
3. Should not catch if returning early in a finally block (infinite loop)
4. It should not leave undone finally statements for uncaught exceptions
5. return should respect finally
6. return should respect catch and finally
7. try/catch/finally should respect continue statements