How to fix missing Copy implementations

[bvssvni]

Rust now uses opt-in Copy, which means the type can be copied implicitly. rust-lang/rust#19566

1. Add #![deny(missing_copy_implementations)] at crate level
2. Put #[deriving(Copy)] where needed

If raw pointers are used, add #![deny(raw_pointer_deriving)] and then add #[allow(missing_copy_implementations)] to each struct that uses a raw pointer.