1. Implement the following mapping rules:
MapAddress a.b.c d.e.f # This is what we have now
MapAddress .a.b.c d.e.f # Replaces any address ending with .a.b.c with d.e.f
MapAddress .a.b.c .d.e.f # Replaces the .a.b.c at the end of any addr with .d.e.f
(Note that 'a.b.c .d.e.f' is invalid, and will be rejected.)
2. Add tests for the new rules.
3. Allow proper wildcard annotation, i.e. '*.d.e' '.d.e' will still work.
4. Update addressmap_entry_t with an is_wildcard member.