Graphical stack (GUI) improvements

[Jakub Jermář]

Implement (a subset of) the following GUI improvements:

• graphics stack improvements
• support for direct rendering in graphic driver infrastructure
• more drawing operations in drawing library (lines, curves, polygons, circles, etc.)
• retained scene description in drawing library
• hardware acceleration of drawing library
• better quality of drawing library output (advanced filtering, antialiasing)
• better precision of drawing library output (floating point coordinates and pixels)
• support for more image and font formats in drawing library
• more widgets in widget toolkit (menu bars, scrolls bars, edit boxes, list boxes, etc.)
• support to minimize and maximize windows
• desktop environment (task bar, icons)
• improvements of terminal emulator (resizing, scrolling, history)
• console applications awareness of resizing and termination of their terminal emulator