Fixes #9
Fixes #11 and #16 by adding IgnoredFIles and IgnoredDirectories that allow you to add any file or directory to be excluded from SaveGame API, the default values are "Player.log" and "output_log.txt" for files and "Analytics" for directories
IOSupported method is now deprecated
Added UsePlayerPrefs option to allow the user to specify whether to use PlayerPrefs as storage or not (otherwise it uses file storage)
Added OnSaving and OnLoading events that occur at the start of the processes