Update for Net-TS Asio (API Change):

fix #769

The following classes are removed:

* handler_type
* async_result
* async_completion
* is_dynamic_buffer
* is_const_buffer_sequence
* is_mutable_buffer_sequence
* handler_alloc

Actions Required:

* Use BOOST_ASIO_HANDLER_TYPE instead of handler_type
* Use BOOST_ASIO_INITFN_RESULT_TYPE instead of async_result
* Use boost::asio::async_completion
* Use boost::asio::is_dynamic_buffer
* Use boost::asio::is_const_buffer_sequence
* Use boost::asio::is_mutable_buffer_sequence
* boost::asio::associated_allocator_t replaces handler_alloc

test/beast/http/parser.cpp

@@ -37,7 +37,7 @@ public:
         parser<isRequest, string_body>;
 
     static
-    boost::asio::const_buffers_1
+    boost::asio::const_buffer
     buf(string_view s)
     {
         return {s.data(), s.size()};