Fix some bugs, normalize code style, update documentation, add tests

Method needs to be public to be useful, updated return type to const
reference for efficiency

changelog.md

@@ -4,6 +4,9 @@ HEAD
 - Examples: Add `print_client_tls` example. This demonstrates a minimal TLS
   client, including basic support via Asio+OpenSSL for certificate chain
   and hostname verification.
+- Feature: Add getter for all headers to the HTTP parsers. This allows a
+  wrapping library to enumerate all headers to send upstream. Thank you Jupp
+  Müller for reporting and an initial pull request.
 - Improvement: Move the `socket_init_handler` to execute as a part of `init_asio`
   rather than connection `pre_init`. This allows setting of socket options prior
   to the bind/listen/accept system calls. Thank you ChristianRobl3D for

test/http/parser.cpp

@@ -506,6 +506,18 @@ BOOST_AUTO_TEST_CASE( basic_request_with_body ) {
     BOOST_CHECK_EQUAL( r.get_header("Host"), "www.example.com" );
     BOOST_CHECK_EQUAL( r.get_header("Content-Length"), "5" );
     BOOST_CHECK_EQUAL( r.get_body(), "abcde" );
+    
+    BOOST_CHECK_EQUAL( r.get_headers().size(), 2);
+    
+    websocketpp::http::parser::header_list::const_iterator it = r.get_headers().begin();
+    
+    BOOST_CHECK_EQUAL( it->first, "Content-Length");
+    BOOST_CHECK_EQUAL( it->second, "5");
+    
+    it++;
+    
+    BOOST_CHECK_EQUAL( it->first, "Host");
+    BOOST_CHECK_EQUAL( it->second, "www.example.com");
 }
 
 BOOST_AUTO_TEST_CASE( basic_request_with_body_split ) {

websocketpp/http/impl/parser.hpp

@@ -176,7 +176,7 @@ inline void parser::process_header(std::string::iterator begin,
                   strip_lws(std::string(cursor+sizeof(header_separator)-1,end)));
 }
 
-inline header_list headers() const {
+inline header_list const & parser::get_headers() const {
     return m_headers;
 }
 

websocketpp/http/parser.hpp

@@ -441,6 +441,16 @@ public:
     bool get_header_as_plist(std::string const & key, parameter_list & out)
         const;
 
+    /// Return a list of all HTTP headers
+    /**
+     * Return a list of all HTTP headers
+     *
+     * @since 0.8.0
+     *
+     * @return A list of all HTTP headers
+     */
+    header_list const & get_headers() const;
+
     /// Append a value to an existing HTTP header
     /**
      * This method will set the value of the HTTP header `key` with the
@@ -590,12 +600,6 @@ protected:
         return (m_body_bytes_needed == 0);
     }
 
-    /// Return a list of all HTTP headers
-    /**
-     * Return a list of all HTTP headers
-     */
-    header_list headers() const;
-
     /// Generate and return the HTTP headers as a string
     /**
      * Each headers will be followed by the \r\n sequence including the last one.