Geometry-rs

Rewrite parts of tidwall/geometry to Rust for ringsaturn/tzf-rs.

toml [dependencies] geometry-rs = "0.1.2"

```rust use std::vec;

use geometry_rs;

fn main() { let poly = geometryrs::Polygon::new( vec![ geometryrs::Point { x: 90.48826291293898, y: 45.951129815858565, }, geometryrs::Point { x: 90.48826291293898, y: 27.99437617512571, }, geometryrs::Point { x: 122.83201291294, y: 27.99437617512571, }, geometryrs::Point { x: 122.83201291294, y: 45.951129815858565, }, geometryrs::Point { x: 90.48826291293898, y: 45.951129815858565, }, ], vec![], );

let p_out = geometry_rs::Point {
    x: 130.74216916294148,
    y: 37.649011392900306,
};

print!("{:?}\n", poly.contains_point(p_out));

let p_in = geometry_rs::Point {
    x: 99.9804504129416,
    y: 39.70716466970461,
};
print!("{:?}\n", poly.contains_point(p_in));

} ```