[cairo] Inserting duplex and tumble options in cairo postscript output

[Lawrence D'Oliveiro]

On Wed, 19 Aug 2015 16:11:32 +0300, Dov Grobgeld wrote:

> The postscript for duplex and tumple typically look as follows:
> 
> statusdict /setduplexmode known
> { statusdict begin setduplexmode end } {pop} ifelse
> statusdict /settumble known
> { statusdict begin settumble end } {pop} ifelse

That seems a pretty antiquated way of doing it, dating back to
PostScript level 1.

See section 6.2 of the PostScript Language Reference Manual for the
preferred way.