signature_scheme lives in Session

not ConnectionFileMixin
mention metadata / display_data similarity in pyout spec
remove pylab from notebook doc
update nbconvert doc

update to new CLI

remove documentation of ill-advised `--script` option.
rename nbconvert doc to nbconvert.rst
add some detail in rst and markdown output
add pandoc note
update payload source

should be simple key, not Python (or worse, IPython) specific long key.

I could have sworn I did this long ago,
but apparently the source key was only updated in display_data,
not execute_reply.
test KernelManager.get_connection_info
Parse markdown correctly when mathjax is disabled
Merge pull request #3831 from minrk/nbdoc

update nbconvert doc with new CLI
Merge pull request #3828 from minrk/signature_scheme

signature_scheme lives in Session

not ConnectionFileMixin

prevents empty signature_scheme in connection files
skip a failing test on windows

soon, the cython magic will move into its own repo and this can be dealt
with properly, but most windows installs will not have a compiler
available out-of-the-box, so it's safer just to skip this altogether
fix incorrect `empty-docstring`

in notebook tooltip.

The else condition wasn't quite right, and would set doctsring to 'empty doctsring'
even when there was a doctoring.
Merge pull request #3849 from ivanov/windows-no-compiler

skip a failing test on windows

in cythonmagic
add missing store_history key to Notebook execute_requests
mention payloads for non-Python kernels

they should be ignored.
Merge pull request #3836 from jhamrick/no-mathjax

Parse markdown correctly when mathjax is disabled

Closes #3835
Merge pull request #3848 from minrk/empty-docstring

fix incorrect `empty-docstring`
Merge pull request #3830 from minrk/pyout_metadata_doc

mention metadata / display_data similarity in pyout spec