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_hep.c

@@ -260,8 +260,8 @@ static struct aco_type global_option = {
 	.type = ACO_GLOBAL,
 	.name = "general",
 	.item_offset = offsetof(struct module_config, general),
-	.category_match = ACO_WHITELIST,
-	.category = "^general$",
+	.category_match = ACO_WHITELIST_EXACT,
+	.category = "general",
 };
 
 struct aco_type *global_options[] = ACO_TYPES(&global_option);