Rename to http::dynamic_body, consolidate header:

fix #284

* streambuf_body is renamed to dynamic_body
* basic_dynabuf_body is renamed to basic_dynamic_body

test/http/dynamic_body.cpp

@@ -0,0 +1,49 @@
+//
+// Copyright (c) 2013-2017 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+// Test that header file is self-contained.
+#include <beast/http/dynamic_body.hpp>
+
+#include <beast/core/to_string.hpp>
+#include <beast/http/fields.hpp>
+#include <beast/http/message_parser.hpp>
+#include <beast/http/read.hpp>
+#include <beast/http/write.hpp>
+#include <beast/test/string_istream.hpp>
+#include <beast/unit_test/suite.hpp>
+#include <boost/lexical_cast.hpp>
+
+namespace beast {
+namespace http {
+
+class dynamic_body_test : public beast::unit_test::suite
+{
+    boost::asio::io_service ios_;
+
+public:
+    void run() override
+    {
+        std::string const s =
+            "HTTP/1.1 200 OK\r\n"
+            "Server: test\r\n"
+            "Content-Length: 3\r\n"
+            "\r\n"
+            "xyz";
+        test::string_istream ss(ios_, s);
+        message_parser<false, dynamic_body, fields> p;
+        streambuf sb;
+        read(ss, sb, p);
+        auto const& m = p.get();
+        BEAST_EXPECT(to_string(m.body.data()) == "xyz");
+        BEAST_EXPECT(boost::lexical_cast<std::string>(m) == s);
+    }
+};
+
+BEAST_DEFINE_TESTSUITE(dynamic_body,http,beast);
+
+} // http
+} // beast