set max packet len to 61 (ie FIFO - length byte - footer) so that corrupted packets (and non-corrupt) having length byte > 61 are discarded. This greatly enhanced stability of the radio
perform a check of the radio and reset it if not ok
simple check-radio-is-ok function, used by SimpleRDC
updated readme
make 9600 baud the default for make login, as that's the LP upper bound for hardware reasons. It can be overrided with eg -b115200 for 115200