Shortening RL_EventData union member names
Fixing actors not getting the correct type at creation
Removing initialization of event data at creation
Adding a RL_ThrowEvent

For when something needs to be set in motion in the world
Fixing the RL_Item not getting correct type at creation
Changing put_actor_in_submap to put_object_in_submap
Made submaps clean up RL_Events properly
Made submaps treat items correctly
Allowed submaps to process RL_ThrowEvents from their inhabitants

Simply dropping items is also handled with a RL_ThrowEvent. (The item is
"thrown" at the same tile with 0 force.)