Settings for articles and feed rendering. Setting these values doesn't mean that changes become visible immediately. This class is only the storage for them.
The objects of this class hold settings data in maps. Access to settings may be provided through simple
get/set
methods or through special accessors (which is preferrable).
Unlike previous revision you don't need to fire any events on changes by hand. Instead, every object notifies all his listeners on change in settings immediately.
Each object may have associated parent object which will be the source of values if current object doesn't have one. NOTE: IT'S ASSUMED THAT EACH PROPERTY HAS ITS VALUE IN THIS INSTANCE OR IN PARENT. IF IT DOESN'T THEN YOU WILL PROBABLY GET NULL POINTER EXCEPTION.
Each object is listening for its parent changes as well and passes events upper only if it has no overwritten value for the property changed in parent object and the changed value affects the returned value of this object during the call to it.