[Click] Make SetUDPChecksum more verbose when something is wrong

[Bart Braem]

Hi,

SetUDPChecksum now uses checked_output_push to output packets it can  
not checksum. However, it would be nice if some warning would be  
output, this silent behaviour is quite hard to debug. I suggest giving  
a warning when packets are in this case, based on a verbose keyword  
that defaults to on.

Regards,
Bart Braem
-- 
Bart Braem
PATS research group - IBBT
Dept. of Mathematics and Computer Sciences
University of Antwerp
Campus Middelheim, G3.30
Middelheimlaan 1
B-2020 Antwerpen, Belgium
Phone: +32 (0)3 265.32.91
Fax: +32 (0)3 265.37.77
Web: www.pats.ua.ac.be