Copy in example code for pygame
Add Greg's arm algorithm from VB for ref
Add first phase with drawing of arm and some geomtry
Add pygame drawing of arm and ability to move it with keyboard
Use previously agreed-upon defaults
Auto-detect 'one' in transform
Force convert to array in canvas_coords
Add world_coords
Add debug mouse motions
Add displacement transformations to canvas
Add zoom with world position preservation
Clean up scaling by encapsulating scale_to in canvas
Draw the disc
Fix prototype of scale_to
Interface for moving the disc and arm
Increase resolution of disc circle
Angle move default to 5 steps, ctrl less, shift more
Allow pressing multiple control keys simultaneously
Use explicit key exclusion in else
Only keep relevant arm data