darcs patch: add withFile and withBinaryFile (#966)

[Samuel Bronson]

On 10/25/06, Ross Paterson <ross at soi.city.ac.uk> wrote:
> Thu Oct 26 01:10:44 BST 2006  Ross Paterson <ross at soi.city.ac.uk>
>   * add withFile and withBinaryFile (#966)
>
>   To be discussed on the libraries list until Thursday 9th November 2006.
>
>   These functions are fairly small, but they're worth naming because they
>   wrap up a pattern that should be encouraged.

I think this bikeshed would be nice in red. (Or: why would it take two
weeks to discuss this?)