Add msp code 238.
Add MSP_MODE_RANGES code to msp.c.
Add 2 extra byte reads to MSP_SET_MODE_RANGES.
Add check for extra bytes in MSP_SET_MODE_RANGES
Add API documentation for MSP_MODE_RANGES_EXTRA
convert linkedTo storage to boxid
Send length of array in EXTRAS data
Add note that alignment of elements of MODE_RANGES and MODE_RANGES_EXTRA is required and indicated by permanentId.