Software Serial, SSOP20 SPI fix, and ISP programmer
Improved Software Serial, better compatibility and 438 bytes smaller code #26 by @jg1uaa
Added 328p variant of SSOP20 and a fix for SPI in this board
#16 by @LaZsolt
Added an ISP programmer for 328p and a menu to set up SERIAL_RX_BUFFER_SIZE as required by it
https://github.com/brother-yan/LGTISP by @brother-yan