Re: Better handling of window margins

[Stefan Monnier]

> My suggestion wasn't supposed to do anything about post-command-hook.
> It aimed only at allowing separate features display in the margins
> without interfering with one another.

WRT to sizing the margin, I think if we want to "do it right" it'd make
sense to provide an Elisp-layer that defines two functions which could
look like:

   (window-margin-register OWNER SIZING-DESCRIPTOR)

and

   (window-margin-unregister OWNER)

so those two functions can appropriately combine the SIZING-DESCRIPTORS
still active.

Not sure what SIZING-DESCRIPTOR should look like (it could be
a function which takes a size and returns a new size).


        Stefan