Add CEntityHandle which wraps an entity_id_t and also has a pointer to a
per-entity array of IComponents. QueryInterface/CmpPtr on a handle just
involve a couple of pointer dereferences instead of a map lookup.
This requires sizeof(void*) per registered interface type per entity,
which is currently ~0.5KB per entity, which shouldn't be a problem.
This was SVN commit r13825.
Cast to smaller integer types explicitly.
Generally avoid platform-dependent types (size_t) in simulation code.
Use float versions of math.h functions, not double.
This was SVN commit r10017.