fuzzy and fuzzyBy produce false positives on long strings (too fuzzy?)

While testing the `fuzzy` and `fuzzyBy` filters on some sample text, I noticed they tend to match any search term for long string data. The longer the text string, the more likely it will match on words that barely resemble the search string. This makes it hard to use effectively, since the filtered results have a very low signal-to-noise ratio.

``` js
var $filter = angular.element(document.body).injector().get('$filter');
var arr = [
{ text: 'foo bar' },
{ text: 'Curabitur ultricies metus eu neque luctus, vitae efficitur ' +
'quam elementum. Aliquam convallis diam et pretium placerat. Morbi ' +
'tellus turpis, sollicitudin eu nunc et, mollis sodales lectus. ' +
'Pellentesque lacinia augue id risus condimentum bibendum.'
}
];
console.log($filter('fuzzy')(arr, 'foobar').length); // returns 2
```