More @nogc, cleanup in ComponentBuffer,
A ComponentBuffer method to get the size of a single component.
ProcessWrapper now provides access to process name.
Minor EntityManager cleanup/refactor.
Fixed a very unpredictable EntityManager heisenbug.
Added a struct to store entity manager diagnostics in.

Includes:

* entity count
* component count
* memory allocated
* memory used
* process calls

and so on and so on.
Stripped EntityManager whitespace.
Accumulating global, per-component-type diagnostics.
Accumulating Process diagnostics (returned by ProcessWrapper).
EntityRange reflects EntityManager property naming change.
EntityManager diagnostics are now accessible through the API.