relax SVN archive

Redesign of how the GPL license is presented to the user.

The old prompt.gpl module with the version 2 of the license has been deleted. Now the text form the
docs/COPYING file is passed through pydoc.pager for the './relax --licence' and the prompt mode GPL
object, and is simply printed to STDOUT for the GUI help system.

Fixes for all of the frame order unit tests for the new maths_fns.frame_order package.

Added some missing imports.

Updated the maths_fns package __all__ list.

Renamed the maths_fns.frame_order.frame_order_matrix_ops module to matrix_ops.

Shifted the maths_fns.pseudo_ellipse module to maths_fns.frame_order.pec.

Removed a pile of unused imports.

Spun out all of the frame order model specific code in frame_order_matrix_ops to separate modules.

Spun out the free-rotor and torsionless pseudo-ellipse target function code into their own modules.

Spun out all of the pseudo-ellipse code from frame_order_matrix_ops into the pseudo_ellipse module.