Updated comments, added types to bring to PHP version 7 level. Updated visibility of fields in classes. Refactored CHILDREN constant.
Updated comments, added types to bring to PHP version 7 level. Updated visibility of fields in classes. Refactored CHILDREN constant.

Signed-off-by: adamculp <e5a4912742f376018a30f9fb7968fb5b85694936@uws.net>

adamculp/refactoring101