Implement automatic cleanup of things specified in a module's spawn() return dict; features the ability to unload modules when we get far enough to make that more public
Restrict modules to 1 function per action; unload was already implemented that way, and it makes the API more consistent (server commands do that as well) and easier to use (no forgetting to put the one function in a list)
Fix each module's spawn output to emit one action function per action without the list
Remove redundant cleanup functions from modules