permissions on installed files

[Nicolas Boulenguez <nicolas.boulenguez@free.fr>]

The policy does says that ALI files must be installed "r--r--r--".

I hardly understand the practical difference with "rw-r--r--", the
common practice for /usr/. The root user can circumvent the
permissions anyway. If we want to warn him that he should not modify
*.ali, why do we let him modify the sources or the compilation options
in the project, invalidating the ali files and causing the same kind
of problems?

I would like opinions about two independant suggestions.
- the policy should enforce the same permissions for all installed files,
  not only ALI files.
- these permissions should be "rw-r--r--" for least surprise.

The subject may seem cosmetic, but debdiff considers this a
difference, making its output quite hard to read.