Latin-1 and Latin-1 supplement font support

Added new sinobit.display.text and sinobit.display.text_width functions that draw text on the full 12x12 sinobit display using the Zpix font. This font covers a wide range of Unicode characters and the firmware includes support for the Latin 1 (0x20-0x7F) and Latin 1 supplement (0xA0-0xFF) characters which cover Latin characters with accents. See the examples/scroll.py demo for a demo of the usage.