Bug#935918: cups: can't read hpcups PPDs

[Till Kamppeter]

Unfortunately, HP has also invented some page size entries named 
"Custom", being a copy of US Legal, for some of their inkjets in 
hpcups.drv. I have fixed this for Ubuntu. See

https://launchpad.net/ubuntu/+source/hplip/3.19.6+dfsg0-1ubuntu1
http://launchpadlibrarian.net/443853073/hplip_3.19.6+dfsg0-1_3.19.6+dfsg0-1ubuntu1.diff.gz

   Till