fix some memory issues

* getaddrinfo is alread allocating the addrinfo struct so we get a
  (quiet small) memory hole
* now checking if malloc failed for whatever reason
* TODO if I startup a varnish and put all traffic at once on it the
  freeaddrinfo is failing (in libjemalloc/jemalloc_linux.c) and I
  don't know why. Probably this is a bug in the libjemalloc but I'm
  not sure about that.
Merge pull request #4 from Savar/fix_memory_stuff

fix some memory issues