the idea is to allow as much internal information into inner components.
to not burden all builds, the reflection level can be controlled
via the MOMO_REFLECTION_LEVEL (where 0 means no reflection code is
included).
more reflection variables will be introduced as needed.
for now, the memory manager's layout version is used to track whether
the memory layout is changed or not (at the lowest level).
the API consumer can use this to decide to refresh or not expensive
computations