readBytes timeout fix and attaching to (USB) RX/TX on ESP32

Fix #136.

Replicate behavior of ESP8266 Stream class, may possibly diverge from readBytes() on AVR:
Timeout must be considered for any period of not receiving any data. Before, it applied unconditionally
to the readBytes() call overall.
Considering body of work over the past year, changing maintainer entry in library descrptor to myself.