fixed make depends for all major platforms (#26)

* fixed 'make depends' building

* fixed capture vars for MacOS

* fixed Linux build for make depends

---------

Co-authored-by: Some Random Crypto Guy <somerandomcryptoguy@protonmail.com>

contrib/depends/patches/unbound/disable-glibc-reallocarray.patch

@@ -1,14 +0,0 @@
-diff --git a/configure.ac b/configure.ac
-index 5c7da197..e2b25288 100644
---- a/configure.ac
-+++ b/configure.ac
-@@ -1702,6 +1702,9 @@ AC_LINK_IFELSE([AC_LANG_SOURCE(AC_INCLUDES_DEFAULT
- #ifndef _OPENBSD_SOURCE
- #define _OPENBSD_SOURCE 1
- #endif
-+#ifdef __linux__
-+# error reallocarray() is currently disabled on Linux to support glibc < 2.26
-+#endif
- #include <stdlib.h>
- int main(void) {
- 	void* p = reallocarray(NULL, 10, 100);

contrib/depends/patches/unbound/no-expat.patch

@@ -0,0 +1,20 @@
+diff --git a/configure b/configure
+index a41e3e1e..7d6a58f0 100755
+--- a/configure
++++ b/configure
+@@ -22053,6 +22053,7 @@ else $as_nop
+    withval="/usr/local /opt/local /usr/lib /usr/pkg /usr/sfw /usr"
+ fi
+ 
++if test x_$withval = x_yes -o x_$withval != x_no; then
+ { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for libexpat" >&5
+ printf %s "checking for libexpat... " >&6; }
+ found_libexpat="no"
+@@ -22090,6 +22091,7 @@ else $as_nop
+   ac_have_decl=0
+ fi
+ printf "%s\n" "#define HAVE_DECL_XML_STOPPARSER $ac_have_decl" >>confdefs.h
++fi
+ 
+ 
+ # hiredis (redis C client for cachedb)