Rhbz1139950 filename mapping

~~this depends on https://github.com/zanata/zanata-api/pull/18~~
We should give some examples in the Javadoc of how these Strings will look like, just to make the code understandable. You have that covered in `pattern` by using the 'glob' description, but lets have a quick example of how it might look like for pattern with the placeholders and all.