Merge pull request #6669 from SylvainCorlay/font_awesome_update

Font awesome update
Merge pull request #6681 from SylvainCorlay/widget_hbox_align

Minor change in widgets.less to fix alignment issue
Improve handling of cursor_start and cursor_end for completions.

Improve handling of cursor_start and cursor_end for completions.

Improve handling of cursor_start and cursor_end for completions.

Fix handling of end != cursor_position

Fix handling of cursor offset and handle end <= start.

Fix handling of cursor offset and handle end <= start.

Reinstate extra whitespace

More whitespace reinstating

Still more whitespace

Finalwhitespace

Add a guard on start

Fix logic for end > cursor_pos

Another ws add

WS tweak

WS again
install local mathjax on Travis

when running the js tests

I'm not sure why loading MathJax from the CDN is falling on Travis,
but it's not happening locally.
Merge pull request #6703 from minrk/install-mathjax-travis

install local mathjax on Travis
Right-justify celltoolbar instead of reversing
Display prompt in the notebook correctly
Display prompts in html nbconvert output
Display prompt numbers correctly in latex output
support buffers in comm messages

- add buffers arg to comm Python api
- support binary websocket messages when buffers are present
- reimplement utf8 in javascript, because javascript is the best
s/unserialize/deserialize
use utf8.js

move message serialization to kernel.serialize module
support binary message from javascript
use TextEncoding for string<->ArrayBuffer

requires text-encoding js polyfill, for now
install text-encoding polyfill
test websocket-friendly binary message roundtrip

Python-side
include buffers when resending message

in zmq.session
test binary websocket messages

only runs on slimerjs for now
unsigned ints for offsets

because signed ints for sizes is icky
move binary msg test to services/serialize