client: simplify API, add StartReadingWait

examples/client-read-h264-save-to-disk/main.go

@@ -163,13 +163,5 @@ func main() {
 	}
 
 	// connect to the server and start reading all tracks
-	err = c.DialRead(inputStream)
-	if err != nil {
-		panic(err)
-	}
-	defer c.Close()
-
-	// read packets
-	err = c.ReadFrames()
-	panic(err)
+	panic(c.StartReadingAndWait(inputStream))
 }