Shorten_long_file_names_preventing_git_checkout.mdwn

Submitting here from https://github.com/joeyh/git-annex/pull/36

    commit 05b7e0d2e87c1c92df773d72ee0ac7c9638be058
    Author: Eric OConnor <eric@oco.nnor.org>

> I've applied this patch. Thanks Eric. 
> 
> Of course, nothing is preventing filenames > 255 being added in the
> future. Based on the number that had to be renamed, this is pretty low
> probability, but it does happen. It would need changes to ikiwiki to add
> an enforced limit. If someone wants to patch ikiwiki that way, I'll
> enable it.
>
> For now, [[done]]. --[[Joey]]