Add an euler filter to the cv-orient twists so we don't get unintended flipping

[tbttfox]

If all of the CV's have 'useOrient' set to 1, and the first and last CV's twist past 180deg relative to each other, and the intermediate CV's are twisted to show a bit of blend, we can get flipping to show up randomly between the intermediate CV's.

The best solution I had is to run an Euler filter down the twists that are controlled by the CV orientation.

[tbttfox]

If you run this, and then twist the last cv, you can see the flipping.

makeTwistSpline('tmp', 5, numJoints=0, spread=3.0)
cmds.setAttr("Ctrl_X_tmpSpline_Part02.rx", -53)
cmds.setAttr("Ctrl_X_tmpSpline_Part03.rx", -162)
cmds.setAttr("Ctrl_X_tmpSpline_Part04.rx", -197)
cmds.setAttr("Ctrl_X_tmpSpline_Part05.rx", -310)
spline = r'Rig_X_tmpSpline_DrvShape'
cmds.setAttr(f"{spline}.debugDisplay", 1)
for i in range(5):
    cmds.setAttr(f"{spline}.vertexData[{i}].useOrient", 1)