ENH: make values from xticks appear

requires update to mplexporter
Merge branch 'axis_fixed_formatter' of github.com:aflaxman/mpld3 into axis_fixed_formatter
update mplexporter submodule hash
Merge pull request #221 from aflaxman/axis_fixed_formatter

ENH: make values from xticks, etc appear
Fixed mpld3.show() for Python 3.4 by calling encoding() on str
Merge pull request #230 from ssabdb/master

Fixed mpld3.show() for Python 3.4 by calling encoding() on str
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
Update index.rst

Direct certain questions to Stack Overflow