Sometimes GameMaker doesn't serialize tile data to disk after changes

[nickavv]

In certain circumstances it seems that changes made to tile layers in the GameMaker Studio 2 room editor will not actually result in changes to the file on disk right away. If Roomsizer is used during this time, it will not have the updated tile layer changes, and will destructively overwrite the tile layer with whatever was last persisted to disk.

We need to either find a way to force GameMaker to persist, or at least somehow check that state in Roomsizer and don't allow destructive resizes.