v0.8.0

• VIC20 emulator, added Download from URL
• Altair8800 emulator, better 88-Disk emulation
• VGA driver: support for Quad Scan
• VGA driver: added 512x192 resolution
• renamed several classes and removed predefined instances
• created DisplayController as base abstract class for all display drivers
• added VGA/Sprites example
• fixed several bugs
• added I2C thread safe class
• added SSD1306 OLED display driver
• added DS3231 real time clock driver
• added new 11 fixed width fonts