use the new parser by default

you can force the old parser with the command line flag
--force-old-config-parser-v4.4-only (which will be present in v4.4 only,
as the name suggests)

include/commands_parser.h

@@ -27,6 +27,11 @@ struct CommandResult {
 
     /* Whether the command requires calling tree_render. */
     bool needs_tree_render;
+
+    /* The next state to transition to. Passed to the function so that we can
+     * determine the next state as a result of a function call, like
+     * cfg_criteria_pop_state() does. */
+    int next_state;
 };
 
 struct CommandResult *parse_command(const char *input);