Check Html Smarty Templates: Parse and check files with HTML or Smarty tags

This class can parse and check files with HTML or Smarty tags.

It can parse a given HTML or Smarty template file and perform checks to find eventual errors. Currently it can:

- Find open tags with close tags,
- Find close tags without open tags
- Check HTML syntax errors

The class displays each error found with the error message and the respective line number.