relax SVN archive

Renamed theta to theta cone (again due to the reversion).

Reverted r9128 to r9133, the elimination of a Euler angle (maybe only temporarily).

The command used was:
svn merge -r9134:9127 .

Bug fix for the cone PDB generation.

If there were more than 1000 protons, the PDB file was corrupted by the proton name being too long.

Bug fix for frame_order.cone_pdb() for when no MC sims exist.

Added checks for the presence of the data structures necessary for frame_order.cone_pdb().

Expansion of frame order to both the forward and reverse rotations.

reduce_alignment_tensor() was renamed to reduce_alignment_tensor_reverse(), and the new function
reduce_alignment_tensor() added.

Wrote the calculate() method for calculating the chi-squared value for the current parameters.

The user can now set the number of increments used to generate the cone PDB.

Made the cone_pdb() function less specific for the N-state model and added SIM as an axis to decorate.

Renamed the axis atom from 'Axe' to 'Axis'.