Vendor dependencies

Let's see how I like this workflow.

vendor/open/src/haiku.rs

@@ -0,0 +1,17 @@
+use std::{ffi::OsStr, io, process::Command};
+
+use crate::{CommandExt, IntoResult};
+
+pub fn that<T: AsRef<OsStr>>(path: T) -> io::Result<()> {
+    Command::new("/bin/open")
+        .arg(path.as_ref())
+        .status_without_output()
+        .into_result()
+}
+
+pub fn with<T: AsRef<OsStr>>(path: T, app: impl Into<String>) -> io::Result<()> {
+    Command::new(app.into())
+        .arg(path.as_ref())
+        .status_without_output()
+        .into_result()
+}