feat(http2): add HTTP/2 support for Client and Server

src/proto/h1/mod.rs

@@ -1,6 +1,8 @@
 pub(crate) use self::conn::Conn;
+pub(crate) use self::dispatch::Dispatcher;
 pub use self::decode::Decoder;
 pub use self::encode::{EncodedBuf, Encoder};
+pub use self::io::Cursor; //TODO: move out of h1::io
 
 mod conn;
 mod date;