Fix: added inspect import to widget.py
Remove init_widget_js, use require.js for everything
Updated examples
Fixed bug with message throttling
Added missing basic_widgets js
Added missing types import
renamed:    basic_widgets.py -> basic_widgets.js
Adding interact.py.
Adding Interact.ipynb notebook.
Adding dict shorthand to interact.
Updating example notebook.
Fixes to interact code for Py 3
Adding call to on_displayed.
Cleaning up commit marks.
Removing init_widget_js.