added a note about sharing of nbconvert tempates
Fixing various output related things:

This was inspired by PR #4105.

* JavaScript output no longer requires calling container.show()
* Added output_javascript CSS class that has zero height when
  empty.
* JavaScript error messages are properly indented with the prompt
  area.
check for libedit in readline on OS X

ensures readline is expressed as setuptools dependency on OS X if libedit is detected.
Merge pull request #4665 from minrk/readline-check

check for libedit in readline on OS X
Merge pull request #4646 from ellisonbg/output-js

Fixing various output related things:

JavaScript output no longer requires calling container.show()
Added output_javascript CSS class that has zero height when empty.
JavaScript error messages are properly indented with the prompt area.
Merge pull request #4650 from ivanov/templates-on-wiki

added a note about sharing of nbconvert tempates
Make non-ASCII docstring unicode
Merge pull request #4668 from takluyver/unicodestdstream-docstring

Make non-ASCII docstring unicode
add missing help strings to HistoryManager configurables

The result was missing information in generated config files.
Fix docstrings in utils.text
Merge pull request #4669 from minrk/history-help

add missing help strings to HistoryManager configurables
Merge pull request #4671 from takluyver/utils-text-docstrings

Fix docstrings in utils.text