Tooltip on toggle button
Make favicon and logo images blocks in the template
[issue3992] set/get use cases for 'env' and new 'set_env' magic
don't execute if kernel is not connected
Don't pass IPython-specific args to non-IPython kernels

add a few FIXME notes that the IPython-kernel special treatment
will probably want to be removed in the Jupyter explosion.
Allow run_line_magic to be called from scripts

Don't blow up if looking back up the stack trace fails.

Reported on rpy2: https://bitbucket.org/lgautier/rpy2/issue/184
/valueerror-call-stack-is-not-deep-enough
Merge pull request #6959 from minrk/check-kernel-execute

don't execute if kernel is not connected
Actually typeset latex
Merge pull request #6965 from takluyver/var-expand-locals-softfail

Allow run_line_magic to be called from scripts
Merge pull request #6953 from mattvonrocketstein/issue3992

[issue3992] set/get use cases for 'env' and new 'set_env' magic
Merge pull request #6923 from SylvainCorlay/toggle_button_tooltip

Tooltip on toggle button
Merge pull request #6881 from jasongrout/template-blocks

Make favicon and logo images blocks in the template
Add debugging print for test failure on Windows
Merge pull request #6970 from takluyver/win-envvar-not-str

Add debugging print for test failure on Windows
More info about erroneous environment variable
Merge pull request #6971 from takluyver/win-envvar-not-str-2

More info about erroneous environment variable
%set_env should ensure environment variables are bytes on Python 2

Should fix test failures on Python 2 + Windows
Cast environment variable key to bytes for Python 2 as well
Merge pull request #6972 from takluyver/fix-win-envvar-not-str

%set_env should ensure environment variables are bytes on Python 2
Output Widget