net-print/cups: Backport patches to restrict IPP Everywhere filters.

Restrict filters we accept for IPP Everywhere configurations to
exactly PDF, JPEG, PNG, PWG-Raster.

URF was added in the original patch but has been explicitly
excluded since we lack the appropriate filter changes.

BUG=chromium:777215
TEST=Verify zeroconf setup still works.

Change-Id: Ief1ab83cfc0f1cb5c7c71740ddf5a1aeed066bcb
Reviewed-on: https://chromium-review.googlesource.com/742381
Commit-Ready: Sean Kau <skau@chromium.org>
Tested-by: Sean Kau <skau@chromium.org>
Reviewed-by: Jorge Lucangeli Obes <jorgelo@chromium.org>
4 files changed