[commit] cleanup stale exec.{h|c} xfer_memory comments.

[Joel Brobecker]

> FWIW, I prefer to have documentation in the header for a module's
> public API, and next to the implementation for the private API.
> Consistency doesn't matter as much to me as being able to read a
> header file and get a grasp of how I would use a module; the private
> comments in the module can then describe the implementation.

I would be OK with this approach too.

-- 
Joel