Fix ClassCast Exception throwed from InkAnalyzer

When I try to analyze a page for ink coverage, the "parseValue" method
was throwing some ClassCastException. It seems like the
DecimalFormat.parse was returning Long. It might be a windows specific
bug.
Merge pull request #18 from BusyBusinessCat/master

FIxing some ClassCastException with InkAnalyzer (method parseValue)