### Fixed
- Raise when invalid turret requested
- Wait before setting slits and mirrors on startup/home so that they are set properly
- Add a stillness check to computation of busy
- things like intermittant firmware busy going low due to e.g. backlashing
- Always loop update state instead of waiting for busy to go true. This ensures the slits are properly read
- previously had be actually setting correctly but not updating reported position
- Avoid trying to set slits to NaN, which would raise an exception and prevent additional slits from being set