Make all default components always have id "default_facet".

This is mainly so that they are easily identified in the AI components overview in the gamestate inspector,
but it can also be used with [modify_ai]. (It replaces the previous use of * for this.)

src/ai/composite/aspect.hpp

@@ -269,8 +269,9 @@ class composite_aspect : public typesafe_aspect<T> {
 			add_facet(-1,cfg_element);
 		}
 
-		const config &_default = this->cfg_.child("default");
+		config _default = this->cfg_.child("default");
 		if (_default) {
+			_default["id"] = "default_facet";
 			std::vector< aspect_ptr > default_aspects;
 			engine::parse_aspect_from_config(*this,_default,parent_id_,std::back_inserter(default_aspects));
 			if (!default_aspects.empty()) {

src/ai/composite/property_handler.hpp

@@ -185,17 +185,17 @@ class facets_property_handler : public vector_property_handler<T> {
 
 	component* handle_get(const path_element &child)
 	{
-		//* is a special case - 'get the default facet'
-		if (child.id == "*") {
+		// special case - 'get the default facet'
+		if (child.id == "default_facet") {
 			return default_.get();
 		}
 		return vector_property_handler<T>::handle_get(child);
 	}
 
 	bool handle_change(const path_element &child, config cfg)
 	{
-		//* is a special case - 'replace the default facet'
-		if (child.id == "*") {
+		// special case - 'replace the default facet'
+		if (child.id == "default_facet") {
 			t_ptr_vector values;
 			this->call_factory(values,cfg);
 			default_ = values.back();