Upon disconnection, the jupyter server apparently returns the same kernel for a given
notebook path input. So reconnect is a thing, and restart is very
distinct from that.
Fixes#377
Coursera appears to kill websockets every minute or so, and I'm
observing firsthand the buggy behaviors described in #356. This PR
cleans up the websocket code and kernel restart logic. Removed
backwards compatibility for the v2 messaging api
as keeping it in the presence of the refactoring would make it more
broken that it already was.
One line change to fix header not updating after cell execution
(keeps saying "Kernel is busy").
The bug does not manifest when running with `ein:debug` true since
EMACS's display loop updates more frequently with debug messages.
In tracking this bug, noticed eldoc support isn't quite there.
`__import__('ein').print_object_info_for(%s)` appears in
`ein-completer` and `ein-pytools`, and is invalid python syntax
afaict. Took a few steps to make it whole, but incomplete.
New hooks `ein:pre-kernel-execute-functions', `ein:on-execute-reply-functions'
and `ein:on-shell-reply-functions'. See variable documentation for more
information.
