Added example plugin how to combine html elements with two-directional communication between IPython server and Javascript code
minor changes to slider plugin notebook
updated example
fixed some typos, added messages that features "not implemented" are not implemented on purpose, added warnings that this notebook uses backend to to calculations and therefore it must be downloaded in order to see any changes
Merge pull request #237 from ahojukka5/slider_example

mpld3 + html elements + communication between javascript / notebook server