Log Message:
Fix build failures on Darwin

patches/patch-src_output_plugins_httpd_HttpdOutputPlugin.cxx:
  Resurrected from the Attic and added some comment.

patches/patch-src_util_Alloc.cxx,
patches/patch-src_util_Alloc.hxx:
  Some platforms (e.g. Darwin 9) don't have strndup(3), but the function
  xstrndup() isn't used in the first place.