Restructure joyent message parser (from Node.js):

* New http::raw_parser wrapper
* Convert parser errors to error_code
* Enumeration and strings for parsed HTTP method
* Move parser engine into joyent namespace
* Rename includes to be distinct

modules/beast_asio/http/HTTPParser.cpp

@@ -22,7 +22,7 @@ namespace beast {
 HTTPParser::HTTPParser (Type type)
     : m_type (type)
     , m_impl (new HTTPParserImpl (
-        (type == typeResponse) ? HTTP_RESPONSE : HTTP_REQUEST))
+        (type == typeResponse) ? joyent::HTTP_RESPONSE : joyent::HTTP_REQUEST))
 {
 }