'unescape' option

Added 'unescape' option to prevent escaping some special characters.
If file has tags like this:
```
<input type="hidden" ng-model="model" ng-init="model='<?php echo $ugly_php_variable; ?>' ">
```

It turns into:
```
<input type="hidden" ng-model="model" ng-init="model=&apos;&lt;?php echo $ugly_php_variable; ?&gt;&apos;''">
```