demo: Fix text color option
text: Fix variable names
text: Remove unused color list
rainbow: Fix typo
tetris: Use form after rotation for fit tests on rotations

Fixes invalid rotations.
Cleanup more row/col mixups
tetris: Remove hardcoded field size
tetris: Ignore movement commands in game over screen
Rename config.R/G/B to config.R/G/B_INDEX
pong: Fix more col/row mixup
demo: Add error checks
text: Add PHP implementation
Rename new_text/images methods to set_new_text/images
Add comment about RGB channel spiltting