Merge pull request #6205 from Carreau/momentjs

use momentjs for nicer dates
Remove errant tabs from js
Change `range` trait to `_range`
Test case for setting only lower or upper, no sensible default so should be an error
Clean up validation in __init__
Merge pull request #6332 from jasongrout/widget-property-lock

Widget property lock should compare json states, not python states
Merge pull request #6050 from chronitis/interact-range-widgets

Range widgets
Merge master
Change from on_demand kwarg to interact_choose function
fix directory listing with broken symlinks

directory listing would 404 if any listed file doesn't exist
(e.g. symlink to missing target).

Previously-failing test included.
build css

looks like a recent PR didn't have a final render of the LESS
add secondary `debug` flag for heartbeats

in both KernelRestarter and parallel HeartMonitor

Since these both produce a huge amount of output,
they limit the usefulness of `--debug` output for debugging
other aspects of IPython.
Merge pull request #6306 from coderforlife/master

Minor improvements to file upload.
fix handling of no-checkpoint-defined

a few typos and missing handling of undefined checkpoint

regression introduced in #6205
minor fixes in dashboard tests

events and regular expressions weren't quite right, which could cause occasional test failures.
Merge pull request #6370 from minrk/handle-no-checkpoint

fix handling of no-checkpoint-defined
Merge pull request #6371 from minrk/dashboard-test-quickfix

minor fixes in dashboard tests
Merge pull request #6359 from minrk/build-css

build css
Remove add/remove class methods,
Remove helper set/get css methods
Fix tests