erlang: Add some initial specs to thrift_client and thrift_protocol

Also add a special header for use in thrift_protocol implementations
that gives specs for the callbacks.

git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@990972 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/lib/erl/src/thrift_binary_protocol.erl b/lib/erl/src/thrift_binary_protocol.erl
index a681acf..a898dfe 100644
--- a/lib/erl/src/thrift_binary_protocol.erl
+++ b/lib/erl/src/thrift_binary_protocol.erl
@@ -37,6 +37,8 @@
                           strict_read=true,
                           strict_write=true
                          }).
+-type state() :: #binary_protocol{}.
+-include("thrift_protocol_impl.hrl").
 
 -define(VERSION_MASK, 16#FFFF0000).
 -define(VERSION_1, 16#80010000).