Some gardening on iptest result reporting
Fix display of notebook directory path
Refactor TestController API to allow it to display extra info.

Add a setup() method to be called when we know we're going to use a test
group, for creating temporary dirs etc., and a print_extra_info() method
to display extra information.
Refactor generation of casperjs command
Fix filenbmanager.list_dirs fails for Windows user profile directory
Fix specifity of flex modifier classes
Re-added already existing base for less backwards compatability.
Fab CSS
remove unnecessary onload hack from mathjax macro
Shorten leftover references to 'IPython test group'
Improve description of -j option to iptest
remove alt-- shortcut

replace with ctrl-shift--

alt is not safe for defaults
use box-flex to layout quickhelp
widen modal dialogs on wide displays

needed for quick help layout with multiple meta keys
Merge pull request #5368 from jdfreder/specifity

Flexbox classes specificity fixes
Merge pull request #5375 from minrk/remove-mathjax-hack

remove unnecessary (?) onload hack from mathjax macro
better log message in deprecated files/ redirect
only check listdir on dirs

is_hidden is called with files, not just dirs
Merge pull request #5326 from takluyver/iptest-gardening

Some gardening on iptest result reporting
Merge pull request #5390 from minrk/finish-5333

finish PR #5333