thread instead of a process for ub_fd() signalling

ChangeLog

@@ -8,6 +8,7 @@
     Stub mode will be the default.  Removes the dependency on libunbound
   * --with-getdns_query compiles and installs the getdns_query tool too
   * Fix assert on context destruction from a callback in stub mode too.
+  * Use a thread instead of a process for running the unbound event loop.
 
 * 2015-07-18: Version 0.3.1
   * Fix repeating rdata fields

src/context.c

@@ -1106,6 +1106,7 @@ rebuild_ub_ctx(struct getdns_context* context) {
 	}
 	/* setup */
 	context->unbound_ctx = ub_ctx_create();
+	(void) ub_ctx_async(context->unbound_ctx, 1)
 	context->unbound_ta_set = 0;
 	if (!context->unbound_ctx) {
 		return GETDNS_RETURN_MEMORY_ERROR;