Debug printf

A fast "printf" debug over the programming interface.

And by fast I mean very fast. Typically around 36kBytes/sec.

./minichlink -T | pv > /dev/null
Found ESP32S2 Programmer
 536KiB 0:00:15 [36.7KiB/s] [        <=>                     ]

You can just try out the debugprintfdemo example, or call SetupDebugPrintf(); and printf() away.