proposed fix for file utility XML bug https://github.com/harvard-lts/fits/issues/103
proposed fix for file utility XML bug https://github.com/harvard-lts/fits/issues/103

There are two problems:
1.) There is a typo within fileutility_to_fits.xslt (two spaces, therefore
    'XML  document text' isn't the same as 'XML document text' => format is empty)
2.) As of file utility version 5.25 the reported output has changed (now with version string)
    file <= 5.24: XML document text
    file => 5.25: XML 1.0 document text, ASCII text

fix:
Use regex in order to identify XML documents and to find XML version.
This works even if no version is provided.

harvard-lts/fits,harvard-lts/fits