untangle includes using iwyu

server/request_parser.cpp

@@ -27,10 +27,16 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include "request_parser.hpp"
 
+#include "http/compression_type.hpp"
+#include "http/header.hpp"
 #include "http/request.hpp"
 
+#include "../data_structures/tribool.hpp"
+
 #include <boost/algorithm/string/predicate.hpp>
 
+#include <string>
+
 namespace http
 {