It's possible for a key to contain whitespace in its name. This breaks the
external special remote protocol, which uses whitespace to separate the key
parameter from subsequent parameters.

I think that this only causes problems for WORM keys. --[[Joey]]

> Ok, went with my last approach, rather than complicating all special
> remotes due to this problem, we'll deprecate WORM keys with spaces in
> their name, and provide a migratipon path.
> 
> The error message looks like this:

> > Sorry, this file cannot be stored on an external special remote because its key's name contains a space. To avoid this problem, you can run: git-annex migrate --backend=WORM

> This is fixed as well as is feasible, so while that kind of sucks,
> calling it [[done]]. --[[Joey]] 
