duplex accounting

Hi Jerome,

Another feature that would be nice, would be the possibility of having
different prices for duplex printings. I know that most likely it would
always charge you for an even number of pages, because that's what the
printer actually counts. To go around this, you could compare the software
accounting with the hardware accounting, and charge by the lesser value.
From the logs, you are already doing this comparison:

Beware : computed job size (2) != precomputed job size (1)

I know it remains the fact of detecting that a job is duplex...

Anyway, it's just a suggestion, that I hope you consider introducing in the
next release 

Best regards,
Elio