Pyleri

* Replace `/` with `_` in function name for c-export.

* Fixed exporting `Repeat` element to C. (issue 9)
* Added header file name option to `export_c()` method.

* 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.

* Added export to JavaScript using class (es6) syntax.

* Use jsleri Ref.set() method instead of Object.assign.

* Format readme on PyPi

* Fixed typo in List mi/ma exception.

* Do not allow duplicate names in lower or upper case.

* Added export to Java for the jleri module.

* Fixed typo indentation.

* Added grammar check for missing START point.