Fix Python 3 bug in demo module
Various polishing of interactive reference doc.
Grammar fix
Don't use fork to start the notebook in js tests

It can encounter a weird segfault on OS X with sqlite when Qt is present (?!)

The main reason to use the fork was to get the port number,
but this is easy now that notebooks write a server-info file.

Further advantage is that the symptom of a failed server start
is no longer silence and hanging tests, but an actual failure with the server's log output.
html and js tests require sqlite3 (session manager)
don't launch js tests if the server didn't start
Fix broken accordion widget,

Also clean-up the code some while visiting this file.
Add displayed property.
and remove logs, commments, etc...
halt stream capturer after server terminates
Make test name match actually file name
Merge pull request #5339 from minrk/iptest-qt-js-wtf

Don't use fork to start the notebook in js tests
Added a test
Merge pull request #5404 from jdfreder/accordion

Fix broken accordion widget
Merge pull request #5330 from takluyver/interactive-reference-updates

Updates to shell reference doc