Further improvements to httphi API (#173)

* add Exchange.WriteBodyString

* Mux.MaxPathValues and other improvements

* Mux PathValue improvemnt and fixes

* MuxSlice more method muxing improvements

* diagram out interesting approach to form parsing for clanker

* refactor RequestParseForm and achieve greatness in API design

* explicit naming of headerCapacityKV value in kvBuffer.Reset

* fix Mux bug not matching paths correctly; httpraw HTTP V1 naming applied

* rename many examples,use httphi in examples,remove useless maxAwaitingConn field

* add ipv4.String

* add ipv4 UnspecifiedAddr and BroadcastAddr

* add ethernet.String

examples/httpraw-client/main.go

@@ -0,0 +1,68 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"net"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"github.com/soypat/lneto/http/httpraw"
+)
+
+func main() {
+	if err := run(); err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+	fmt.Println("DONE")
+}
+
+func run() error {
+	var port int
+	flag.IntVar(&port, "lport", 13337, "Local port over which to hit server")
+	flag.Parse()
+	// Prepare GET request.
+	var hdr httpraw.HeaderV1
+	hdr.SetMethod("GET")
+	hdr.SetRequestTarget("/")
+	hdr.SetProtocol("HTTP/1.1")
+	req, err := hdr.AppendRequest(nil)
+	if err != nil {
+		return err
+	}
+
+	fmt.Println(time.Now().Format("15:04:05.000"), "dialing...")
+	conn, err := net.DialTCP("tcp4", &net.TCPAddr{IP: []byte{192, 168, 10, 1}, Port: port}, &net.TCPAddr{IP: []byte{192, 168, 10, 2}, Port: 80})
+	if err != nil {
+		return err
+	}
+	defer conn.Close()
+	go func() {
+		c := make(chan os.Signal, 1)
+		signal.Notify(c, os.Interrupt, syscall.SIGTERM)
+		s := <-c
+		fmt.Println("terminating connection on signal", s.String())
+		conn.Close()
+		os.Exit(0)
+	}()
+	fmt.Println(time.Now().Format("15:04:05.000"), "writing...")
+	conn.Write(req)
+	hdr.Reset(nil, 0) // No preallocation. Both key/value and raw buffer will grow and allocate.
+	var needMore bool = true
+	for needMore {
+		_, err = hdr.ReadFromLimited(conn, 1024)
+		if err != nil {
+			break
+		}
+		const asResponse = true
+		needMore, err = hdr.TryParse(asResponse)
+	}
+	if err != nil {
+		return err
+	}
+	fmt.Println(time.Now().Format("15:04:05.000"), "got HTTP:\n", hdr.String())
+	return nil
+}