gtk: integrates GtkBin in the hierarchy

A GtkBin is a container that contains only one child
Comments on core classes

Signed-off-by: Nathan Heu <heu.nathan@courrier.uqam.ca>
gtk: add some state method to GtkWindow

Signed-off-by: Nathan Heu <heu.nathan@courrier.uqam.ca>
gtk: new widgets and base classe Misc

Signed-off-by: Nathan Heu <heu.nathan@courrier.uqam.ca>
gtk: add enumeration modules and new widgets

Add modules for gtk and gdk enumerations
New widgets dervied from button : ScaleButton, LinkButton,...

Signed-off-by: Nathan Heu <heu.nathan@courrier.uqam.ca>
gtk: add Entry, Scrollbar and Ranges widget

Signed-off-by: Nathan Heu <heu.nathan@courrier.uqam.ca>
gtk: refactor structure of library

Signed-off-by: Nathan Heu <heu.nathan@courrier.uqam.ca>
gtk: add a couple of -lower interest- widgets

Signed-off-by: Nathan Heu <heu.nathan@courrier.uqam.ca>
gtk: add graphical assistants widgets

Signed-off-by: Nathan Heu <heu.nathan@courrier.uqam.ca>
gtk: add basic dialog widget and derived dialog windows : about, appChooser, fileChooser, message,...

Signed-off-by: Nathan Heu <heu.nathan@courrier.uqam.ca>
gtk: add license terms

Signed-off-by: Nathan Heu <heu.nathan@courrier.uqam.ca>