lua: overhaul lua support
- vendor a specific version in
- disallow modules by default (or at all)
- do proper sandboxing, both for security and performance
- enable it by default so rule vendors can rely on it to be there
Neovim has some discussion on why they use Lua 5.1 vs other versions:
Also, rlua, the previously most popular Lua bindings for Rust started with Lua 5.3 I think. 5.1 came after due to popular demand. mlua, a fork of rlua that seems to be more popular now, and also supports luajit 5.1.
By using one of these crates we can get Lua vendored for free.