jupyter js widget image display broken from groovy

[scottdraves]

[scottdraves]

http://ipywidgets.readthedocs.io/en/stable/changelog.html says:

Custom serializers can now return a structure that contains binary objects (ArrayBuffer, DataView, or a typed array such as Int8Array, Float64Array, etc.). In this case, the sync message will be a binary message, which is much more efficient for binary data than base64-encoding. The Image widget now uses this binary synchronization. (jupyter-widgets/ipywidgets#1194, jupyter-widgets/ipywidgets#1643)