Use svg by default due to lack of Ghostscript by default on Windows
Make the default plot type platform dependent
remove configurable.created

closes #4612
Allow process_handler to accept a list of arguments
Use argument lists for testing command help output.

Avoids quoting and escaping issues if there is a space in
sys.executable.

Closes gh-4629
Merge pull request #4631 from takluyver/i4629

Use argument lists for command help tests
Merge pull request #4613 from minrk/configurable-created

remove configurable.created
Merge pull request #4446 from blink1073/master

Use SVG plots in OctaveMagic by default due to lack of Ghostscript on Windows Octave
Adding prompt area to non-CodeCells to indent content.

This is a reponse to the problem of having really long lines in
Markdown cells, which makes the content difficult to read. Users
want wide code cells, so we don't want to narrow everything. The
solution here is to give a prompt area to the heading/md cells
to narrow their content area slightly. The only problem is that
this makes it more difficult to distinguish between output
and md content that follows that output. The solve this, we are
adding a narrow line between output and following md.
Removing style to delimit output as per dev meeting.
Merge pull request #4567 from ellisonbg/indent-cell

Adding prompt area to non-CodeCells to indent content.

prompts now appear in the margin of the document.