Assorted bits (#138)

* LCN

* Prevent deprecated compiler warning

* Implement huge function numbers

* new commands

<! [cab]> forget locos.
<9> ESTOP ALL.
<D RESET> reboot arduino

* Waveform accuracy msg

* Drop post-write verify

* UNUSED_PIN current measure

and callback -2 for cv actions.

* Correct diags

* ESTOP a forget loco

* ESTOP loco on forget

* Avoid compiler warning

* current sensor offset

* Restore <1 JOIN> after prog track operation

* <!> ESTOP <-> FORGET

* Auto current offset detection

* manage current offset and diagnostics

* neater msg at startup

* Add startup message to LCN master

* DCC::setJoinRelayPin

Co-authored-by: Asbelos <asbelos@btinternet.com>

MotorDrivers.h

@@ -21,7 +21,7 @@
 // If the brakePin is negative that means the sense
 // of the brake pin on the motor bridge is inverted
 // (HIGH == release brake)
-
+//
 // Arduino standard Motor Shield
 #define STANDARD_MOTOR_SHIELD F("STANDARD_MOTOR_SHIELD"),                                                 \
                               new MotorDriver(3, 12, UNUSED_PIN, UNUSED_PIN, A0, 2.99, 2000, UNUSED_PIN), \