Add basic alpha version of the UE4 plugin

[XAMPPRocky]

Adds the basic initial version of the UE4 client, right now it just attaches a routing token and version to the end of the packet.

[markmandel]

Apache licences on everything please.

I know nadda about UE4. @luna-duclos would yourself, or someone else at Embarl be good to review this? (unless it already has?)

The only other thought I have, is that we should reference this in our book somewhere. Maybe a new "SDKs" section?

[markmandel]

Another thought on having someone with UE4 knowledge give a LGTM - just to double check everything is included, and where it should be. Not something I can do.

[bombsimon]

I can't say I'm an UE4 expert but this code looks good to me, properly structured as UE4 plugin and just wraps the FUniqueSocket for all calls.

LGTM!

[markmandel]

I can't say I'm an UE4 expert but this code looks good to me, properly structured as UE4 plugin and just wraps the FUniqueSocket for all calls.

LGTM!

Awesome. Then the only thing blocking for me is getting some documentation into the Guide!

[quilkin-bot]

Build Succeeded 🥳

Build Id: 49ee321e-f6d3-4921-a1b3-4d32f7e8305c

To build this version:

git fetch git@github.com:googleforgames/quilkin.git pull/485/head:pr_485 && git checkout pr_485
cargo build