Re: Overlay mechanic improvements

[Stefan Monnier]

> [[[ To any NSA and FBI agents reading my email: please consider    ]]]
> [[[ whether defending the US Constitution against all enemies,     ]]]
> [[[ foreign or domestic, requires you to follow Snowden's example. ]]]
> I don't see that it makes sense to store overlays like text properties.
> The existing data structure is fine for overlays used as they are intended
> to be used.

The data structure used is too naive, with an algorithmic complexity
that can be problematic.  Moving it to a balanced binary tree with turn
O(N^2) complexity into O(N log N).


        Stefan