migrate remaining code to the new maps

examples/word_counter/word_counter.v

@@ -26,10 +26,7 @@ fn main() {
 		m[key] = m[key] + 1// TODO m[key]++
 	}
 	// Sort the keys
-	mut keys := []string
+	mut keys := m.keys() 
-	for e in m.entries {
-		keys << e.key
-	}
 	keys.sort()
 	// Print the map
 	for key in keys {

vlib/builtin/map.v

@@ -202,7 +202,7 @@ pub fn (m map_string) str() string {
 	}
 	// TODO use bytes buffer
 	mut s := '{\n'
-	//for entry in m.entries {
+	//for key, val  in m { 
 		//val := m[entry.key]
 		//s += '  "$entry.key" => "$val"\n'
 	//}

vlib/http/http_mac.v

@@ -124,9 +124,7 @@ fn (req &Request) do() Response {
 	// Add request headers
 	mut hlist := &C.curl_slist{!}
 	// for i, h := range req.headers {
-	for entry in req.headers.entries {
+	for key, val in req.headers {
-		key := entry.key
-		val := req.headers[key]
 		h := '$key: $val'
 		hlist = C.curl_slist_append(hlist, h.cstr())
 	}

vlib/http/http_win.v

@@ -42,10 +42,7 @@ fn (req &Request) do() Response {
 	mut headers := ''
 	mut resp_headers := ''
 	// for header in req.headers {
-	for entry in req.headers.entries {
+	for key, val in req.headers {
-		// headers += '$header\r\n'
-		key := entry.key
-		val := req.headers[key]
 		headers += '$key: $val\r\n'
 	}
 	if req.typ == 'POST' {