Here lie implementation details that should be explained but aren't part of the
public-facing API.

Component Representation
========================
Mobs implementing CMI are required to keep track of a black box containing a
mob's component data in a _cmi_components field. The actual representation is a
table with these fields:

old_serialization: A map from component names to their serialized form from when
they were last deserialized. This is kept track of to prevent mobs from losing
information in case a mod is accidentally uninstalled.

components: A table from component names to their current data.