ArduPlane: optional interlock on arm/disarm and EStop #332

Job	Run time
build (stm32f7, chibios, 10)	12m 3s
build (stm32h7, chibios, 10)	10m 58s
build (fmuv2-plane, chibios, 10)	4m 47s
build (periph-build, chibios, 10)	10m 45s
build (iofirmware, chibios, 10)	1m 51s
build (CubeOrange-bootloader, chibios, 10)	57s
build (fmuv3-bootloader, chibios, 10)	1m 9s
build (revo-bootloader, chibios, 10)	51s
build (stm32h7-debug, chibios, 10)	6m 21s
build (fmuv3, chibios, 10)	13m 33s
build (revo-mini, chibios, 10)	9m 48s
build (MatekF405-Wing, chibios, 10)	10m 25s
build (CubeOrange-ODID, chibios, 10)	7m 52s
build (CubeRedPrimary-bootloader, chibios, 10)	58s
build (configure-all, chibios, 10)	11m 25s
build (build-options-defaults-test, chibios, 10)	22m 24s
build (signing, chibios, 10)	8m 3s
build (CubeOrange-PPP, chibios, 10)	6m 15s
build (CubeRed-EKF2, chibios, 10)	6m 20s
build (SOHW, chibios, 10)	9m 52s
build (Pixhawk6X-PPPGW, chibios, 10)	2m 0s
build (new-check, chibios, 10)	12m 13s
	2h 50m 50s

Provide feedback