Update Helper.php

1. Update method escape: 
Call function htmlspecialchars () sufficient if encoding supports all characters in the input string (such as UTF-8, but also ISO-8859-1 for input only ISO-8859-1). Need to call the function htmlentities () appears only when the output encoding does not support all the characters from the input string.

`http://php.net/manual/ru/function.htmlspecialchars.php`

2 Small typo fixes