GGVM picker font provenance

The selected 8x8 VGA font is Daniel Hepper's font8x8 data, based on Marcel
Sondaar / International Business Machines public-domain VGA fonts. The
upstream source states that its license is Public Domain. The retained
source-local legend remains in font8x8.h; rows are reversed for VIC-II pixels.
https://github.com/dhepper/font8x8
