splix: revert of revert of "2.0.0 -> svn-r315 version update"

This reverts commit e338d6a0. I originally
reverted the update because it broke my Samsung printer. Now, it turns out that
this issue can be fixed by deleting and then re-creating the printer in CUPS to
update the driver.

It's possible that Gutenprints 'cups-genppdupdates' could remedy the situation
as well, but I had no chance to verify that since I don't use Gutenprint.

Closes https://github.com/NixOS/nixpkgs/issues/13734.