Blender Git Commit Log

When iserting rotations in poses, the quaternion sometimes rotates exactly
the opposite way as you want. Or even worse, you can never really define
which way it rotates (officially it should do shortest path).

This hotkey flips the quaternion (which means it rotates to same position
exactly via the other way). Hotkey ALT+F (flip) in 3d window posemode.