Update Debian policy for Multi-Arch

[Francois Gouget <fgouget@free.fr>]

A large number of packages, particularly development packages, are not 
multi-arch aware. This raises the barrier of entry for performing 32 bit 
development on a 64 bit system and actively hurts some projects like 
Wine where it is very important to be able to compile both versions.

Looking into this I found that multi-arch was a release goal of Debian 7 
(Wheezy) and that it is marked as completed:

https://wiki.debian.org/ReleaseGoals/


So I looked to see whether the Debian Policy was saying multi-arch is a 
should, a must or something else.

It turns out it does not say anything of value: multi-arch is mentioned 
as being an exception to the FHS in section "9.1.1 File System 
Structure" and in footnotes 60, 78 and 79. That's all!


That does not seem compatible with multi-arch being a completed goal of 
the old-stable release. So what about adding a section like this:


   3.10 Multi-arch support

   Packages must be multi-arch aware and architecture-specific 
   development packages must be tagged as Multi-Arch: same.


-- 
Francois Gouget <fgouget@free.fr>              http://fgouget.free.fr/
 Advice is what we ask for when we already know the answer but wish we didn't
                                 -- Eric Jong