Marking -doc packages as Multi-Arch: foreign

[Colin Watson <cjwatson@debian.org>]

Looking through http://bootstrap.debian.net/cross_all.html, there's a
lot of noise from Haskell packages.  I know that cross-building Haskell
code is going to be fairly tough and we aren't going to make the problem
go away just by tweaking a bit of packaging metadata, but for the sake
of making the report size smaller for everyone else, would anyone object
to us adding "Multi-Arch: foreign" to all our -doc packages?  (This
seems a little counterintuitive if you're unfamiliar with multiarch -
people often ask why "Architecture: all" isn't sufficient - but
https://wiki.ubuntu.com/MultiarchSpec#Dependencies_involving_Architecture:_all_packages
explains it.)

We wouldn't need to upload immediately for this, just stage it in git
for the next mass upload.

Note that haskell-devscripts can't be handled as easily, because it
depends on the compiler.  However, I think it would be safe to make
dh-haskell Multi-Arch: foreign as long as it doesn't start depending on
the compiler (from a cross-building point of view it is definitely
simpler if it doesn't!), since it only depends on packages that expose
architecture-independent interfaces.

Thanks,

-- 
Colin Watson                                       [cjwatson@debian.org]