Multilib doc packages

[orion cora nwra com]

There appears to be on the order of 340MB of -doc, -docs, and -javadoc
i386 packages in the x86_64 development repository.  Presumably these will
be nearly identical to the x86_64 versions.  Perhaps it might be
worthwhile excluding them?  Not worth the effort if we are just going to
move to arch specific repositories...

- Orion