Since all feature-negotiation processing now takes place in feat.c,
functions for producing verbose debugging output are concentrated
there.

New functions to print out values, entry records, and options are
provided, and also a macro is defined to not always have the function
name in the output line.

Thanks a lot to Wei Yongjun and Giuseppe Galeota for help and
discussion with an earlier revision of this patch.
Signed-off-by: NGerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: NIan McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>