Rework gutenprint derivation:
* Convert to regular stdenv.mkDerivation;
* Enable IJS driver;
* Fix cups-genppdupdate;
* Move things around to the proper directories;
* Enable parallel building;
* Clean from old hacks.
This is used to generate ppd files for cups:
$ cups-genppd.5.2 -M | grep p50
canon-cp500
escp2-p50
$ cups-genppd.5.2 -p . escp2-p50
This will create the relevant ppd file in the current directory. This
can then be used by cups after setting services.drivers.drivers =
[pkgs.gutenprint]; and configuring the printer to use this ppd e.g.
via the web interface on http://localhost:631