Silence compiler warning about using deprecated actor state access macros by using functions introduced with Clutter 1.23.4

We update the source code to use state access functions, e.g. clutter_actor_is_visible(), instead of the old macros, e.g. CLUTTER_ACTOR_IS_VISIBLE(). But also implement a compatibility layer which "redirects" functions to macros again when compiling and linking against Clutter older than 1.23.4.

This is the first fix for issue GH #117