[hplip] (4 commits) ...Merge branch 'f20' into f21

[Tim Waugh]

Summary of changes:

  01eac0e... Potential fix for lineart scanning (bug #1076954). (*)
  622424b... Reverted previous change as it didn't help (bug #1076954). (*)
  298dff8... Updated udev-rules patch so that firmware is reloaded on de (*)
  d20386e... Merge branch 'f20' into f21 (*)

(*) This commit already existed in another branch; no separate mail sent