This file holds the `jupyter-connection` type which is an intermediate
successor of `jupyter-comm-layer` on the way towards more functional
kernel I/O.
To make up for this:
- Move the functions defined in `jupyter-connection.el` to `jupyter-base.el`
- Add a `session` field to the `jupyter-kernel-manager` and `jupyter-channel`
classes
- Add a `kernel-info` field to the `jupyter-repl-client`
- Add a `conn-info` field to a `jupyter-session`
- Add a `session` field to `jupyter-kernel-client`
This way when creating kernel clients with `jupyter-kernel-manager`, we can set
the `parent-instance` of the newly created client to the manager thereby
inheriting the `jupyter-session` from the kernel manager.
Also have `jupyter-channel` objects inherit from a `jupyter-connection` so that
we can define `jupyter-send` and `jupyter-recv` methods for channels in the future.
- `jupyter-client.el` only contains client related code
- `jupyter-kernel-manager` related code is placed in `jupyter-kernel-manager.el`
- Socket creating functions and generating connection info plist function are
placed in `jupyter-connection.el`. This also contains the
`jupyter-connection` class.
- Kernelspec related functions are placed in `jupyter-kernelspec.el`
- Move general utility functions and variables requires necessary for `jupyter`
into `jupyter-base.el`. This also contains the `jupyter-session` and
`jupyter-request` struct definitions.
