o Major refactoring:
    - Refactor the get_interface_addresses_raw() Doom-function into
      multiple smaller and easier to understand subfunctions. Cover the
      resulting subfunctions with unit-tests. Fixes a significant portion 
      of issue 12376.

  o Minor bugfixes:
    - Fix the ioctl()-based network interface lookup code so that it will
      work on systems that have variable-length struct ifreq, for example
      Mac OS X.