merge with debian-experimental-ma

merge with debian-experimental-ma

* Swedish translation update. Closes: #592366
* apt-pkg/pkgcache.cc:
  - re-evaluate the architectures cache when the cache is (re)opened
* apt-pkg/cdrom.cc:
  - fix off-by-one error in DropBinaryArch
* apt-pkg/contrib/fileutl.cc:
  - Add WriteAtomic mode.
  - Revert WriteEmpty to old behavior (LP: #613211)
* apt-pkg, methods:
  - Convert users of WriteEmpty to WriteAtomic.
* apt-pkg/depcache.cc:
  - Only try upgrade for Breaks if there is a newer version, otherwise
    handle it as Conflicts (by removing it) (helps for #591882).
* debian/control:
  - Add dependency on gnupg to apt, apt-key uses it.