Add two famous old versions of autoconf

These old versions are often used because their immediate successors are incompatible in some way.

var/spack/repos/builtin/packages/autoconf/package.py

@@ -34,6 +34,8 @@ class Autoconf(Package):
 
     version('2.69', '82d05e03b93e45f5a39b828dc9c6c29b')
     version('2.62', '6c1f3b3734999035d77da5024aab4fbd')
+    version('2.59', 'd4d45eaa1769d45e59dcb131a4af17a0')
+    version('2.13', '9de56d4a161a723228220b0f425dc711')
 
     depends_on('m4', type='build')