Alpha ai pacenotes: rally stages & pacenotes editor v0.5.2-alpha

This update brings a major new feature: "dynamic codriver"

You no longer have to manually place audio triggers. Instead, the vehicle's position and speed are used to play the pacenote a certain number of seconds ahead of the corner.

Known issue: sometimes the vehile tracker can lose track of the vehicle, and pacenotes stop playing. You can fix this by driving backwards on the course to the last pacenote you heard, and turn around. We're working to track down this issue and make it completely reliable.