There is no good solution here, since RNA props can only have one type/unit. Tried to find the less worse one - have different RNA props for same DNA value (a bit like the angle/length for camera lens). Also fixed two other issues with Transform conctraint: * Angle were still in degrees (yes, another backward-compatibility breacking). * Scale was absolute, unlike loc/rot. Also cleaned up a bit the code, replaced some magic numbers by proper enums, ...