Fix coordinates in the whiteboard drawing.
Added StackedWidget class.
Improved StackWidget
Merge branch 'GUI-refactoring' of https://github.com/matteozajac/Jamii into GUI-refactoring
Added example of stackedWidget usage on page2.html
web_page fix
Merge branch 'GUI-refactoring' of https://github.com/alekgajos/Jamii into GUI-refactoring