ldns: fix compilation without deprecated APIs

Refreshed darwin patch.

The first OpenSSL patch is an upstream backport. The second was sent
upstream: https://github.com/NLnetLabs/ldns/pull/68

Small Makefile cleanups for consistency.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

libs/ldns/patches/001-compile-for-darwin.patch

@@ -1,8 +1,6 @@
 --- a/configure.ac
 +++ b/configure.ac
-@@ -859,10 +859,10 @@
- AC_ARG_WITH(xcode-sdk, AC_HELP_STRING([--with-xcode-sdk], 
-  [Set xcode SDK version. Default is autodetect]), 
+@@ -881,7 +881,7 @@ AC_ARG_WITH(xcode-sdk, AC_HELP_STRING([--with-xcode-sdk],
   [],[with_xcode_sdk="yes"])
  if test "x_$with_xcode_sdk" != "x_no" ; then
     # check OSX deployment target, if needed