THRIFT-4176: Implement threaded server for Rust
Client: rs

* Create a TIoChannel construct
* Separate TTransport into TReadTransport and TWriteTransport
* Restructure types to avoid shared ownership
* Remove user-visible boxing and ref-counting
* Replace TSimpleServer with a thread-pool based TServer

This closes #1255
diff --git a/lib/rs/Cargo.toml b/lib/rs/Cargo.toml
index 07c5e67..be34785 100644
--- a/lib/rs/Cargo.toml
+++ b/lib/rs/Cargo.toml
@@ -11,8 +11,9 @@
 keywords = ["thrift"]
 
 [dependencies]
+byteorder = "0.5.3"
 integer-encoding = "1.0.3"
 log = "~0.3.6"
-byteorder = "0.5.3"
+threadpool = "1.0"
 try_from = "0.2.0"