Improve Network and Serial library web reference

- fix broken `@see_external` webref links (remove outdated LIB_ prefix)
- adjust `@instanceName`s and descriptions to match the webref example
  variable names

java/libraries/serial/src/processing/serial/Serial.java

@@ -39,9 +39,9 @@ import jssc.*;
  *
  * @webref serial
  * @webBrief Class for sending and receiving data using the serial communication protocol
- * @instanceName serial any variable of type Serial
+ * @instanceName myPort your Serial object
  * @usage Application
- * @see_external LIB_serial/serialEvent
+ * @see_external serialEvent
  */
 public class Serial implements SerialPortEventListener {
   PApplet parent;