Create wrapper around properties with convient helper methods

[tobiasdiez]

Similar to the EasyObservableValue there should be an EasyObservableProperty that exposes some of the methods (like selectProperty) so that they can be chained together.

For example, the interface could look like

Property<Boolean> binding = EasyBind.wrapProperty(control.sceneProperty()) 
                                    .select(s -> s.windowProperty()) 
                                    .select(w -> w.showingProperty());