Log Message:
Upgrade to 0.4:

0.4 (Jan 2014)
  - bugfix: fix a bug in new list code introduced in 0.3
  - portability: use $(LD)/$(LDFLAGS)/$(LIBS)

0.3 (Jan 2014)
  - bugfix: refactor double-linked list implementation in udns_resolver.c
      (internal to the library) to be more strict-aliasing-friendly,
      because old code were miscompiled by gcc.
  - bugfix: forgotten strdup() in rblcheck