* jupyter-base.el: Don't add `jupyter-server-mode--unset-client-soon` to
`server-switch-hook` at toplevel
(jupyter-server-mode-set-client): Add `jupyter-server-mode--unset-client-soon`
to `server-switch-hook` if necessary.
* jupyter-client.el: (jupyter--run-callbacks): Use `when-let`.
(jupyter--set-callback): Remove.
(jupyter--add-callback): Use `add-function`.
* jupyter-ioloop.el (jupyter-ioloop-add-arg-type): Use `setf` along with `alist-get`.
(jupyter-ioloop--replace-args): Use `pcase`.
(jupyter-ioloop--event-dispatcher): Extract out event cases into variable `user-events`.
(jupyter-ioloop--body): New function.
(jupyter-ioloop--function): Use it.
* jupyter-kernel-process-manager.el
(jupyter--kernel-died-process-sentinel)
(jupyter-stop-channels): Use `when-let`.
* jupyter-org-client.el (jupyter-org-interaction-mode): Use `cl-callf2?`.
* jupyter-server.el: Add TODO.
* jupyter-tramp.el: Remove unused function declaration.
So as to further generalize and separate out the abstract kernel manager class
from its various implementations.
* jupyter-kernel-manager.el (jupyter-meta-kernel): Fix documentation.
(jupyter-kernel-process, jupyter-command-kernel, jupyter-spec-kernel):
Move related functions and methods to `jupyter-kernel-process-manager.el`
(jupyter-kernel-manager-base): Remove class.
(jupyter-kernel-manager): Re-purpose class as the base class of all kernel
managers. The class corresponding to the old functionality is now named
`jupyter-kernel-process-manager`. Move all related functions and methods for
`jupyter-kernel-process-manager` to `jupyter-kernel-process-manager.el`.
* jupyter-kernel-process-manager.el: New file.
* jupyter-repl.el: Require `jupyter-kernel-process-manager` instead of
`jupyter-kernel-manager`.
* jupyter-server.el (jupyter-server-kernel-manager): Inherit from
`jupyter-kernel-manager` instead of `jupyter-kernel-manager-base`.
* test/jupyter-test.el (jupyter-kernel-lifetime)
(jupyter-command-kernel): Use `jupyter-kernel-process-manager` instead of
`jupyter-kernel-manager`.
* test/test-helper.el: Require `jupyter-kernel-process-manager` instead of
`jupyter-kernel-manager`.
