Add failing test for gh-3459
Add failing test for completing arguments after '%run foo.py '
Improve matching files after script name for magic %run.

Closes gh-3459
Add failing test for duplicate dirs in completions
Fix duplicate directories in %run tab completion
Partially normalise paths for Windows tests
Audit .html() calls take #2
Move todos into set_rendered
s/with with/with
Treat set_rendered as unsafe.
Use set_rendered to set the error msg of the cell.
add ascii_only filter
require latex titles to be ascii

otherwise the ucs package barfs all over itself
Children fire event

Now when a container widget is displayed, the _handle_displayed method
of each of its children is fired.
jshint
DEBUG

Added lots of log calls and a couple small 'fixes' (attempts)
Fixed lots of bugs

Half overhaul of notebook focus events...
Use is_focused for element kbman removal event
Added cell unfocus event canceller API
Fixed rebase problems