Added screenbufer library for better rendering performance.
The display library now uses screenbuffer.
Removed redirection from screen library.
Changed gui library rendering process. Now uses screenbuffer for containers.
Added imageio library. Added support for NFP and NFT image formats.
Added colors.invert function.
Added appmake tool to create .app files.
Added sysmon and mpaint programs (both still unfinished).
Bug fixes and minor tweaks.