handle nodejs executable on debian

closes #5201
Merge pull request #5202 from minrk/nodejs-garbage

handle nodejs executable on debian
fix pyreadline import in rlineimpl

it installs readline.py
Wrap nbconvert Markdown/Heading cells in live divs

Addresses https://github.com/ipython/ipython/issues/5206

This partially mimics the live IPython notebook layout, but is not a
complete solution.
Allow to pass option to jinja env

Mainly to pass cache_size=-1 while developping not to cache templates
Merge pull request #5200 from Carreau/jinja-no-cache

Allow to pass option to jinja env
Merge pull request #5212 from ahmadia/ahmadia/div_layout_fix

Fix mismatch of div/css in nbconvert and live notebook.
Merge pull request #5210 from minrk/pyreadline

fix pyreadline import in rlineimpl
Merge pull request #5197 from jasongrout/traitlet-notify

If there is an error comparing traitlet values when setting a trait, default to go ahead and notify of the new value.