- several parameters are now const
- OS-specific code moved from iface_mgr.cc to iface_mgr_linux.cc
- C-style casts replaced with a casting framework
  (see lib/util/io/pktinfo_utilities.h)
- added lib/util/range_utilities.h for methods that operate on
  container's ranges (isRangeZero and fillRandom)
- many other minor corrections