Update glyphs visualization

This introduces bug fixes to all glyph based visualization (namely ODF and tensors). The main one being that when you dropped an image alone with a non identity orientation, slicing was corrupted. Now it's corrected.

Opacity has also been added to vector and SH visualization. We'll have to see if we keep Mike's branch or add this one on top of it.
pos is not supposed to be modified so having SetCurrentPosition(const double pos[3]) won't hurt. Especially also since the one with int has const as well