[Ruby] Image Science crashes Mongrel

[ben wiseley]

I think this is a pretty serious bug in Image Science... it just crashed our
production box...

If you create a text file, rename it test.jpg and resize it with
ImageScience mongrel crashes immediately, no errors to trap on, nothing...
just kills it.

We're going to try a hack and use the Unix "file" command and parse it's
results to try to prevent this... anyone have a more elegant solution?  I
don't know of a way to tell if an image file is really an image file from
Ruby... does something like that exist?

-ben