aco: Minimize use of regex.

Remove nearly all use of regex from ACO users.  Still remaining:
* app_confbridge has a legitamate use of option name regex.
* ast_sorcery_object_fields_register is implemented with regex, all
  callers use simple prefix based regex.  I haven't decided the best
  way to fix this in both 13/15 and master.

Change-Id: Ib5ed478218d8a661ace4d2eaaea98b59a897974b

res/res_statsd.c

@@ -231,8 +231,8 @@ static struct aco_type global_option = {
 	.type = ACO_GLOBAL,
 	.name = "global",
 	.item_offset = offsetof(struct conf, global),
-	.category = "^general$",
-	.category_match = ACO_WHITELIST
+	.category = "general",
+	.category_match = ACO_WHITELIST_EXACT,
 };
 
 static struct aco_type *global_options[] = ACO_TYPES(&global_option);