Allow environment variables to override default autotools.

diff --git a/ares/buildconf b/ares/buildconf
index 3e61b9e..c1d0d03 100755 (executable)
--- a/ares/buildconf
+++ b/ares/buildconf
@@ -1,7 +1,7 @@
 #!/bin/sh
 
-libtoolize --copy --automake --force
-aclocal
-autoheader
-autoconf
-automake --add-missing
+${LIBTOOLIZE:-libtoolize} --copy --automake --force
+${ACLOCAL:-aclocal}
+${AUTOHEADER:-autoheader}
+${AUTOCONF:-autoconf}
+${AUTOMAKE:-automake} --add-missing