message: add missing logging examples
diff: extern crate rlibc;
  extern crate spin;
  -// These need to be visible to the linker, so we need to export them.
  -pub use runtime_glue::*;
  -
  #[macro_use]
  mod macros;
  +#[macro_use]
  +mod logging;
  mod runtime_glue;
  mod console;
  +// These need to be visible to the linker, so we need to export them.
  +pub use runtime_glue::*;
  +pub use logging::*;
  +
  #[no_mangle]
  pub extern "C" fn rust_main() {
  println!("Hello from Rust!");
  +
  + info!("hello");
  + //warn!("warning");
  + //error!("oops");
  }
  