No multiarch support

[dnord]

When trying to install codecs for multiarch setup it turns out that `libmjpegutils-2.1-0` and `libmjpegutils-2.1-0:i386` cannot be installed together so I cannot have both `gstreamer1.0-plugins-bad` and `gstreamer1.0-plugins-bad:i386`. I suspect it is some packaging error, but loss to find a cause.

Distribution: Ubuntu 16.04 (xenial)
Package: libmjpegutils-2.1-0
Version: 1:2.1.0+debian-4

$ sudo apt install libmjpegutils-2.1-0 libmjpegutils-2.1-0:i386
Reading package lists... Done
Building dependency tree
Reading state information... Done
libmjpegutils-2.1-0 is already the newest version (1:2.1.0+debian-4).
libmjpegutils-2.1-0 set to manually installed.
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 libmjpegutils-2.1-0 : Conflicts: libmjpegutils-2.1-0:i386 but 1:2.1.0+debian-4 is to be installed
 libmjpegutils-2.1-0:i386 : Conflicts: libmjpegutils-2.1-0 but 1:2.1.0+debian-4 is to be installed
E: Unable to correct problems, you have held broken packages.

[dnord (dnord)]

While libs are correctly installed to arch-dependent paths like /usr/lib/i386-linux-gnu and /usr/lib/x86_64-linux-gnu multiarch support is not provided for some reason, which results in this conflict.

[dnord (dnord)]

I think simply adding `Multi-Arch: same` to all libraries in question will solve this problem, as path are already architecture-dependent.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Derek Gasaway (derekbga)]

It might also be sane to mark the mjpegtools package with Multi-Arch: allowed (or foreign), as programs that use the binary tools may not care what architecture the tools are.