Vendor dependencies

Let's see how I like this workflow.

vendor/users/examples/list.rs

@@ -0,0 +1,16 @@
+extern crate users;
+use users::{User, all_users};
+
+extern crate env_logger;
+
+
+fn main() {
+    env_logger::init();
+
+    let mut users: Vec<User> = unsafe { all_users() }.collect();
+    users.sort_by(|a, b| a.uid().cmp(&b.uid()));
+
+    for user in users {
+        println!("User {} has name {}", user.uid(), user.name().to_string_lossy());
+    }
+}