This also improves Palette so it stores the original RGB888 colors. Lastly, it adds I2CDisplay as a display bus to talk over I2C. Particularly useful for the SSD1306. Fixes #1828. Fixes #1956
Instead remember and use the frequency, polarity and phase that was set when the bus was first created.
microDev
Scott Shawcroft
Radomir Dopieralski