Move tokio_kcp to local files

src/plugins/kcp/mod.rs

@@ -0,0 +1,14 @@
+//! Library of KCP on Tokio
+
+pub use self::{
+    config::{KcpConfig, KcpNoDelayConfig},
+    listener::KcpListener,
+    stream::KcpStream,
+};
+
+mod config;
+mod listener;
+mod session;
+mod skcp;
+mod stream;
+mod utils;