libgdnsd refactor, no functional change at all.

This shifts the anysin_t data type down into libdmn as
  dmn_anysin_t, and moves the associated text->anysin_t
  convertors and log formatters for that data type down
  as well.  Back-compat for the old gdnsd-specific type
  and function names, etc, was kept via #defines.

Zero real impact on gdnsd itself, but moving more generic
  utility functionality down to libdmn is helpful at the
  moment, in pursuit of the longer-term goal of splitting
  libdmn out as an independent shared lib.