Making a nrepl server

[scrabsha]

Title says basically everything.

Development will live on my fork. Feel free to make any comment about the implementation here.

Here is the minimum set of things that must work before a PR is created:

• ability to connect a lein client to the server,
• add proper CLI handling to decide whether if we start a nrepl server or drop in a regular repl,
• handle multiple connections at the same time.

Most of the work here is inspired of the implementation of borkdude's nrepl server.

Below is a more detalled todo list of what needs to be done:

• start a basic server, listening to a predefined port,
• add a way to deserialize requests to a rust HashMap,
• handle the clone operation,
• handle the eval operation,
• figure out if we need to send some ack or not,
• handle other necessary but still not discovered operations,
• discuss about whether if different connections should be able to share defined functions,
• handle proper cli (see Erkk comment on discord),
• get testing from various people, with various setups.

If you have any question or suggestion, feel free to comment on this issue or to contact me on Discord.

[scrabsha]

Commit 9ffcc60 adds an implementation of eval.