Edit all rules that match a specified description.

        @description - The description to match against.
        @key         - The key to change for each matching rule.
        @value       - The new key value for each matching rule.

        Returns the number of rules modified.

def edit_rules(self, description, key, value):
        '''
        Edit all rules that match a specified description.

        @description - The description to match against.
        @key         - The key to change for each matching rule.
        @value       - The new key value for each matching rule.

        Returns the number of rules modified.
        '''
        count = 0
        description = description.lower()

        for i in range(0, len(self.extract_rules)):
            if self.extract_rules[i]['regex'].search(description):
                if has_key(self.extract_rules[i], key):
                    self.extract_rules[i][key] = value
                    count += 1

        return count