- `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.
