Fixed the problem with pointers and vectors reallocating memory

Made the over function, sprite changes to blue.
return value for widget update
Widgets adapt to window's size
Added Observable patern class
Splitted code and now trigger widgets using the observers system
Can now trigger panels from widgets

Still working on cleaning the code.
Panels can now be hidden or displayed
need to replace the string event by a flag
Now pass a t_event struct to notify observer
documented AWidget.hpp file
Added doc for APanelScreen.hpp
Finished and corrected the widget/panel implementation

Need to fill the trigger method from all the event it can receive
Merge branch 'develop' into menu
removed warnings