new tab placed at end of tabbar
MenuBar, ToolBar, StatusBar and Actions moved to files
x and y coordinates of main window may be saved to settings file
deleted TopBar component
restored CanvasArea, BrushLibrary, BrushSettings and LayerManager
added relativeX and relativeY properties to ToolWindow
deleted CloseButton component
removed dark style from SliderText component
restored About component
fixed External WM_DESTROY error
added spacing between slider and scrollview viewport in BrushSettings