[PATCH] add documentation about backend naming for VMOD authors

[Dridi Boukelmoune]

>>If both VMODs rely on a vcl_name to name their backends (myvcl.mydir)
>>then they can't get in this situation. That's my whole point.
>
> And in a VCL which uses two different VMODs which create dynamic
> backends ?

We can't have two VMOD objects from different VMODs (or even from the
same VMOD) having the same vcl_name for a given VCL. That's a
guarantee we get from libvcc.

> No matter what, I don't think this is panic material, unless the VMOD
> writer feels that way about it.

As I said, I don't feel strongly about panicking or returning NULL and
letting the VMOD writer deal with it. It's the suffix suggestion I'd rather
avoid.

Dridi