A variety of useful utilities on Aabr and Aabb

[zesterer]

I'm using both of these types a lot at the moment while doing dungeon generation for Veloren ( https://www.veloren.net ) so I'm trying to distill the biggest API pain points down into a series of additions that should help those that come after me.

[yoanlcq]

CI checks only failed because of cargo test --features "serde repr_simd" on Nightly. Sad thing I didn't notice it beforehand, but at least cargo build is not broken... I've commited a fix.

[yoanlcq]

By the way, it's always nice hearing about vek being used for cool stuff! :+1: I'm also all for more erognomics in the API.

[zesterer]

A few screenshots of dungeons generated using vek.