- Copy correct data to our lookahead buffer. It was previously missing the media...

 - Copy correct data to our lookahead buffer. It was previously missing the media header which messed up the lookahead buffer size passed to ProtocolReceive
 - Fix the check for loopback indication. It was previously checking whether the source and destination packets were the same which makes no sense at all
 - Correct the offset and length passed to NdisCopyFromPacketToPacket. The caller's values of these don't include the header size but the packet does
 - Fixes a crash when running "ping 10.0.2.15 -l 1800" on vbox with NAT

svn path=/trunk/; revision=43635