Resolved issue with inability to parse non-UTF-8 catalogs. Internal logic changed: now passing IO object (not String) to Nokogiri XML Parser. Changed corresponding specs.
refactoring according to repo owner's comments
tiny syntax refactoring
changed dup of io to rewind
Merge pull request #2 from liptonshmidt/fix/non_utf-8_encoding_recognition

Resolved issue with inability to parse non-UTF-8 catalogs.