Rust rewrite

[TOTBWF]

When I originally made this project, I wanted to keep it pretty minimal, so C was the best option. However, in order to add features, quite a bit of string munging is required, for which C isn't the best option. On top of that, support for messaging, etc would be nice, and to be entirely honest I don't want to deal with that in C.

With those points in mind, I have been considering doing a re-write of the project in Rust. I just wanted to get some feedback from those that might actually be using the project.

[TOTBWF]

So the things left to do on this are:

• add support for multiple steamapp directories
• make sure that the wine stuff still works
• update docs on how to build/update AUR pkgbuild

Beyond that, it looks like this is (finally) ready to ship