Changed the scope of the validate() method to protected from public as this method is called outside from the class.
- Added the `validate()` and `content()` methods for the meta box and page meta box factory classes.
Fixed a local variable name to avoid being misleading.
Cleaned inappropriate comments.
- Fixed code formatting to be defensive against potential mistakes.
- Renamed a method to make it clear what it does.
Changed a method name to make it clear what it is for.
Fixed code formatting for better readability.
- Added the `options_update_status_{...}` and `validation_saved_options_without_dynamic_elements_` filters for the admin page factory class.
- Added the `field_definition_{...}` filters for the page meta box class.
- Added the `validate()` and `content()` methods for the meta box and page meta box factory classes.
- Changed not to lose the input data when a form validation error occurs for the page meta box class.
- Fixed a bug that the old options of the second parameter passed in a validation callback method of the page meta box class did not hold dynamic elements.
Resolves #172.
- Advanced the version number to help identify the changes.
- Generated the minified version to reflect the changes.