AppArmor prevents the user from adding a USB printer

Originally created by @emmapeel on #10893 (Redmine)

Trying to add a printer in Tails 2.0beta

- Plug printer

- Open System settings/Printers/Add a printer
- Choose printer from the menu (appears twice, same result with both entries)

Nothing happens. No error message.

On dmesg I see:

[  318.270237] audit: type=1400 audit(1452509365.533:27): apparmor="DENIED" operation="exec" profile="/usr/sbin/cupsd" name="/usr/lib/cups/backend/ipp14" pid=26342 comm="cups-deviced" requested_mask="x" denied_mask="x" fsuid=7 ouid=0
[  890.408040] usb 4-2: new full-speed USB device number 2 using ohci-pci
[  890.583072] usb 4-2: New USB device found, idVendor=03f0, idProduct=7e04
[  890.583084] usb 4-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[  890.583090] usb 4-2: Product: Deskjet F4100 series
[  890.583095] usb 4-2: Manufacturer: HP
[  890.583099] usb 4-2: SerialNumber: CN86N7W36904TJ
[  891.711455] WARNING! power/level is deprecated; use power/control instead
[  891.824787] usblp 4-2:1.1: usblp1: USB Bidirectional printer dev 2 if 1 alt 0 proto 2 vid 0x03F0 pid 0x7E04
[  891.824828] usbcore: registered new interface driver usblp
[  897.548273] usblp1: removed
[  897.555304] usblp 4-2:1.1: usblp1: USB Bidirectional printer dev 2 if 1 alt 0 proto 2 vid 0x03F0 pid 0x7E04
[  917.788871] usblp1: removed
[  917.795185] usblp 4-2:1.1: usblp1: USB Bidirectional printer dev 2 if 1 alt 0 proto 2 vid 0x03F0 pid 0x7E04
[  920.632645] audit: type=1400 audit(1452509967.896:28): apparmor="DENIED" operation="exec" profile="/usr/sbin/cupsd" name="/usr/lib/cups/backend/ipp14" pid=27863 comm="cups-deviced" requested_mask="x" denied_mask="x" fsuid=7 ouid=0
[  925.336417] usblp1: removed
[  925.343255] usblp 4-2:1.1: usblp1: USB Bidirectional printer dev 2 if 1 alt 0 proto 2 vid 0x03F0 pid 0x7E04
[  928.080211] audit: type=1400 audit(1452509975.344:29): apparmor="DENIED" operation="exec" profile="/usr/sbin/cupsd" name="/usr/lib/cups/backend/ipp14" pid=27918 comm="cups-deviced" requested_mask="x" denied_mask="x" fsuid=7 ouid=0
[  933.564877] usblp1: removed
[  933.571120] usblp 4-2:1.1: usblp1: USB Bidirectional printer dev 2 if 1 alt 0 proto 2 vid 0x03F0 pid 0x7E04
[  936.350413] audit: type=1400 audit(1452509983.612:30): apparmor="DENIED" operation="exec" profile="/usr/sbin/cupsd" name="/usr/lib/cups/backend/ipp14" pid=27971 comm="cups-deviced" requested_mask="x" denied_mask="x" fsuid=7 ouid=0
[  942.100303] usblp1: removed
[  942.107265] usblp 4-2:1.1: usblp1: USB Bidirectional printer dev 2 if 1 alt 0 proto 2 vid 0x03F0 pid 0x7E04
[  944.875028] audit: type=1400 audit(1452509992.136:31): apparmor="DENIED" operation="exec" profile="/usr/sbin/cupsd" name="/usr/lib/cups/backend/ipp14" pid=28024 comm="cups-deviced" requested_mask="x" denied_mask="x" fsuid=7 ouid=0

IIRC Printers are not persistent in this install. Will confirm when rebooting.

Feature Branch: bugfix/10893-printer-ipp4