check orientation angles

[butler]

Paul Kienzle has identified what he believes is a serious bug. The documentation suggests that Phi is the angle the particle's primary axis makes with the beam direction and theta the angle the particle's primary axis makes in the plane perpendicular to the beam.

However he believes these have been reversed in the code and is causing an unphysical symmetry in the scattering pattern visible under certain conditions. Others have oft complained of being confused when playing with these parameters which could easily be due to this as well.

We must verify this and fix it properly before releasing 4.0 which we expect, among other things to make 2D analysis more accessible.