relax SVN archive

Instead of being stored as a list or array of numbers in cdp.pivot, the point is now stored as
cdp.pivot_x, cdp.pivot_y and cdp.pivot_z. The second pivot cdp.pivot2 is now stored as
cdp.pivot_x_2, cdp.pivot_y_2 and cdp.pivot_z_2.

This is to simplify the automated handling of optimisation parameters. Rather than having to
convert the pivot_x, pivot_y, and pivot_z parameters to and from a list, the same mechanisms can now
be used for all of the optimised frame order parameters. This will be used to hugely simplify many
of the functions in the specific_analyses.frame_order.parameters module and eliminate a large source
of bugs.