add some save stat in debug.
replace few std::string by const&.
fix actor destructor not virtual.
add Saving/Loading event trigger when a save start to save/load.
REVERT THIS COMMIT!
Merge branch 'feature/save_log_stat' of git://github.com/asmodehn/WkCocos into game/dragonfall
Revert "improving version check and DLC."

This reverts commit 6de0b936dcff3ba4d09f05e4d99fd8c74726e283.