Cleanup of some unused variables.
Count bad checksums.
Add "echo" command for testing.
Fix some const/non-const issues.
Add forgotten eeprom source files.
Fix off-by-one-error in content generation.
enc: reset transmitter when it becomes stuck (see errata).
Add leds positions/features to port list.
Introduce more subtile approach to eth/mac/phy errors, which does
seem to work better, previous "blunt" approach tends to hangup
the SPI bus.
Add upd4 support.
Rearrange Makefile so default compilation is -O2 and
exceptions for -O0.
Make more variables static.
Stats

- move text stats generation into stats.c
- change size from 16 to 8 bits, saves ram and output