Added MicroVAX I network boot support

pdp11_xq.c, pdp11_xq.h
	- Added emulation and visibility to the LEDs which were on the physical DEQNA/DELQA network boards.  "show xq: will now display the LED state in addition to the other useful things.
	- Added debugging of loopback packet data
	- Avoided padding on short loopback packets
	- Added support for extended length loopback packets (up to 1600 bytes) which is described in the DEQNA manual and used by the MicroVAX I boot ROM.  Recieve such packets with the LONG error indicator.
	- Returned 'reserved' status bits as 1's in received packet status word 1.
	- Added debug display of transmit and receive Buffer Descriptor List contents.

sim_ether.c, sim_ether.h
	- Added support for extended/oversized packets.
4 files changed