Added support for logging save events

I am not a python dev but by reading through the ST documentation I found the right API calls to implement event logging on saving a file. This is useful for the cases where you create a new file in ST (from what I understand, `on_load()` wouldn't trigger under these circumstances).

Please ignore the superfluous changes around lines 11 and 21. Looks like my editor just changed the tabs/indentation around.