ensure scp destination directories exist (with mkdir -p)

in SSH launchers.

As described in #3411

closes #3411
Add edit/command mode indicator.
Adding PDFFormatter and kernel side handling of PDF display data.
Adding support for multiple figure formats in InlineBackend.
Making figure_format config=True.
Adding top level IPython.display.select_matplotlib_formats.
Docstring improvement.
Refining the matplotlib APIs in IPython.display.
Adding basic append_pdf in OutputArea.
Spinning sun + nothing for command mode.
make execute button in menu bar match shift-enter

Noticed this when testing the UI on the IPad.
I expected the button to perform the default execute behavior,
but it doesn't.
remove %pylab from pylab-switching
move pylab-switching to mpl-switching
pylab_figshow -> inline_figshow
remove pylab from desktop entrypoint and completion
remove pylab from internal_ipkernel example
remove pylab from the parallel examples
don't mention `--pylab` in R or cell magic notebooks
use mpl showcase instead of pylab examples

for %load
show traceback in widget handlers

rather than logging

closes #5064