Implement dragging of rotation handle in texturing view.

Signed-off-by: Kristian Duske <kristian.duske@gmail.com>
Minor changes.
Rotation now works for some faces, but it depends on the texture normal.

Signed-off-by: Kristian Duske <kristian.duske@gmail.com>
Use the correct Z axis in the paraxial texture coordinate system conversion matrices.

Signed-off-by: Kristian Duske <kristian.duske@gmail.com>
Add method to precisely measure a texture rotation angle to texture coordinate system.
Change all enum names to avoid name clashes.

Signed-off-by: Kristian Duske <kristian.duske@gmail.com>