SMFFragProg: branching--
! LuaSyncedCtrl: cleanup arg-parsing of Spring.SetUnitPieceCollisionVolumeData

new signature: SetUnitPieceCollisionVolumeData(
  number unitID,
  number pieceIdx,
  boolean enable,
  number scales.x,
  number scales.y,
  number scales.z,
  number offset.x,
  number offset.y,
  number offset.z
  [, number volumeType
  [, number primaryAxis]]
)

(the behavior of this callout last changed in 0.83 but not its
signature and the backward-compatibility was highly obfuscating)