Limit/control pin state reporting option

- As a setup feature, users can compile-in input pin status reporting.
Doesn’t do anything special, just prints the binary for the port. 0’s
and 1’s indicate low and high signals on the pins. It’s a bit cryptic
right now, but it’s just a start.

- Added a max step rate check when writing step/mm and max rate
settings. Should help avoid people misdiagnosing problems associated
with going over the 30kHz step rate limit. Right now not enabled. Takes
up over 100k of flash. Need that room for other things right now.

report.h

@@ -33,6 +33,7 @@
 #define STATUS_ALARM_LOCK 9
 #define STATUS_SOFT_LIMIT_ERROR 10
 #define STATUS_OVERFLOW 11
+// #define STATUS_MAX_STEP_RATE_EXCEEDED 12
 
 #define STATUS_GCODE_UNSUPPORTED_COMMAND 20
 #define STATUS_GCODE_MODAL_GROUP_VIOLATION 21