added unbound to external deps

external/unbound/libunbound/python/doc/examples/example5.rst

@@ -0,0 +1,29 @@
+.. _example_resolver_only:
+
+==============================
+Resolver only
+==============================
+
+This example program shows how to perform DNS resolution only.
+Unbound contains two basic modules: resolver and validator.
+In case, the validator is not necessary, the validator module can be turned off using "module-config" option.
+This option contains a list of module names separated by the space char. This list determined which modules should be employed and in what order.
+
+::
+
+	#!/usr/bin/python
+	import os
+	from unbound import ub_ctx,RR_TYPE_A,RR_CLASS_IN
+	
+	ctx = ub_ctx()
+	ctx.set_option("module-config:","iterator")
+	ctx.resolvconf("/etc/resolv.conf")
+	
+	status, result = ctx.resolve("www.google.com", RR_TYPE_A, RR_CLASS_IN)
+	if status == 0 and result.havedata:
+	
+	    print "Result:", result.data.address_list
+
+.. note::
+   The :meth:`unbound.ub_ctx.set_option` method must be used before the first resolution (i.e. before :meth:`unbound.ub_ctx.resolve` or :meth:`unbound.ub_ctx.resolve_async` call). 
+