VFP and VDP configurations

[Dridi Boukelmoune]

> - format specifiers:
>
>         - have:
>
>           (gzip), (plain) *1), (esi)
>
>         - ideas:
>
>           (br), (buffertext) *2)
>
>         esi being a format which can contain gzip segments, but that's would
>         be opaque to other vfps
[...]
> *1) "(text)" in reza's concept

Or "identity" to match HTTP vocabulary.

> *2) not sure if this is a good idea, maybe multi segment regexen are the better
>     idea

For a lack of better place to comment, in my previous message I put
`content` before `assembly`. On second thought it should be the other
way around, otherwise <esi> tags break the content type.

Dridi