Vulnerable Regular Expressions#212

The following regular expressions used in underscore and unescapeHTML methods are vulnerable to ReDoS: ```js /([A-Z\d]+)([A-Z][a-z])/g /\&([^;]+);/g ``` The slowdown is moderately low (for 50,000 characters around 2 seconds matching time). I would suggest one of the following: - remove the regex, - anchor the regex, - limit the number of characters that can be matched by the repetition, - limit the input size. If needed, I can provide an actual example showing the slowdown.