Jibb: ent_purge makes no significant change.

MrGuest: My expample was meant to show that creating a terrain and deleting it
later does NOT release all its used memory. And that is their limitation.
Youve got to realise that the plan is to have a never-ending world,
so that means that level_load never gets used, except when entering or leaving the world.
And the terrains Im creating are FLAT and I apply my own height-map to the vertices
during run time. And when the terrain is too far away to be seen, it gets put
into 'limbo' as a spare. When it gets pulled out of limbo for re-use,
it gets a DIFFERENT height-map applied.
So Im not re-using the terrain SHAPE, just the entity itself.