boards/z80/ez80/z20x/configs/w25boot/defconfig: Increase size of serial Tx buffer.
boards/z80/ez80/z20x/src/w25_main.c: Add some fflush() in necessary places. Greatly improves the usability of the UI.
boards/z80/ez80/z20x/README.txt: Trival update to README
drivers/serial/serial.c and tcdrain.c: Correct some typos.