Rewrite std::comm

* Streams are now ~3x faster than before (fewer allocations and more optimized)
    * Based on a single-producer single-consumer lock-free queue that doesn't
      always have to allocate on every send.
    * Blocking via mutexes/cond vars outside the runtime
* Streams work in/out of the runtime seamlessly
* Select now works in/out of the runtime seamlessly
* Streams will now fail!() on send() if the other end has hung up
    * try_send() will not fail
* PortOne/ChanOne removed
* SharedPort removed
* MegaPipe removed
* Generic select removed (only one kind of port now)
* API redesign
    * try_recv == never block
    * recv_opt == block, don't fail
    * iter() == Iterator<T> for Port<T>
    * removed peek
    * Type::new
* Removed rt::comm

src/libstd/lib.rs

@@ -203,15 +203,16 @@ pub mod rt;
 mod std {
     pub use clone;
     pub use cmp;
+    pub use comm;
     pub use condition;
     pub use fmt;
+    pub use io;
     pub use kinds;
     pub use local_data;
     pub use logging;
     pub use logging;
     pub use option;
     pub use os;
-    pub use io;
     pub use rt;
     pub use str;
     pub use to_bytes;