better debugging

better debugging

dev/ns_gige.cc:
    Make all DPRINTF statements take one line. If they need two lines,
    break them up into separate statements.  This makes grep much more
    effective since *every* line will be prefixed by the cycle that the
    trace message is from and the object that caused the message.
    normalize some debugging statements so that searching is easier
    (e.g. always say rxState, not rx state or receive state)
    break into the debugger when a packet is dropped since we don't really
    like dropping packets.

--HG--
extra : convert_revision : 9cf309ca2143a6b8c8215ac5dd6a31aae60173cd