PDP10, PDP11, VAX780, VAX750, VAX730: Fixed DMC/DMR DDCMP implementation to be tolerant of packet corruption.
PDP10, PDP11, VAX: Fix DMC/DMR DDCMP implementation to not crash due to buffer exhaustion while generating NAK packets for missing packets.
PDP10, PDP11, VAX: Fixed Sync Data corruption Troll to actually discard transmit packets which it thinks it wants to.
PDP10, PDP11, VAX: Fixed DMC/DMR DDCMP implementation to only send a single NAK when a data packet arrives out of order.
PDP10, PDP11, VAX: Fix out of order packet numbers after processing some NAK data.  Also restart outgoing packet flow consistently if an output stall occurred.
PDP10, PDP11, VAX: Fix buffer leak while generating NAK messages