Blender Git Loki

Fix T40271: recalculation of the bone roll does not work correctly.

Check that up_axis is not aligned with bone was wrong in at least two aspects
(not working against negative alignement case, and since ages it seems,
using Z axis when bones are along Y axis...).

Also optimized a bit here, better to have a normalized version of vec_roll_to_mat3(),
since it needs normalized vector anyway, and we have to normalize it for the tests
before calling it anyway (so now, we only do that twice in Transform code, instead
of three times).

And we can perform aling test *before* calling vec_roll_to_mat3!