1.3.0

• Added element properties:
  • Keyword.ign_case
  • Choice.most_greedy
  • List.min, List.max, List.opt_closing
  • Repeat.min, 'Repeat.max`
• Added Result.as_str() method for returning a textual parse result.
• Fixed correct expecting for List element.
• Added MaxRecursionError exception for Prio element.
• Added create_grammar() method as a shortdut for writting a Grammar class.