Removes attribute of controller in mainwindowview
Changes Load to Open in menu
Create basic open menu
Displays categories with duplication issues
Fixes category panel issue
Adds methods to select a new category
Adds categories with correct ids
retrieve correct button category
Fixes issue in loop to retrieve category button
Display sprites
Repaints sprite panel when displaying new sprites
Reset screen when new project opened
Displays only little sprites and shows all in tooltip