.fd files

[David Carlisle]

Thanks (as ever) to Ulrik for the careful reading.

> ^^ who is `we'?
er good question.
Mostly the new  docstrip is the work of Marcin Woli\'nski with the
new functions limiting the number of concurrently open files done in
conjunction with Mark Wooding. Most of the text I posted was Marcin's
although I had shuffled it around a bit while merging in the new
version into the forthcoming release.

>            isn't that actually tex/generic/babel?
yes I believe it should be.
Actually it is a lie at the moment as the current babel 3.5 and 3.6beta
setups don't use this at all, but I'll change the docs anyway.

> Hmmm.  Would it be forseeable to allow inserting some appropriate
> system-specific commands at this point (via the .cfg) in order to use
> execute a  `mkdir $TEXMF/whatever/needed' e.g. via the new \write18{}
>   feature in web2c-7.0.

Hmm yes, it would be foreseeable but no, I don't think I'll mention that
in the docs just yet.

David