Add notion of action that differs from  shortcuts.

This decouple the notion of shortcut from the notion of executed "action"
This allow the shortcuts manager to be purely describe as data, and the
same action to be later refered to either from the shortcut, from a toolbar
button or a menu.

This also implement a more complete keyboard shortcut handler which is
able ton interpete sequences like `Cmd-X,Meta-v` By storing the
shortcuts in a tree.
remove debug
add test warning shadow
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.
Actually typeset latex
Public server firewall configuration

Added section on firewall configuration.  This should prevent users (like me) from struggling
to figure out why their servers aren't executing code.
Fixed port range

Actual port range for ZMQ is 49152 through 65535.  Also fixed some grammar/spelling issues.
Output Widget
Make output widget reactive.
Added comment describing output area stack.
Pop output now removes a specific output
active_output_areas (plural)
Address @carreau 's comments
Bug fix, typo
Add doc string to Output widget
Merge pull request #6670 from jdfreder/output_widget

Output widget
Merge pull request #6955 from Carreau/typeset

Actually typeset latex
update MappingKernelManager module docstring
Don't dismiss rename dialog until rename is complete

- draws error message in the same dialog,
rather than triggering a new dialog via events.

- `Notebook.rename` returns the contents Promise, rather than registering its own error handler.
Merge pull request #6961 from minrk/profile-dir-no-3p

Don't pass IPython-specific args to non-IPython kernels