relax SVN archive

Bug fix for the generic_fns.sequence.generate() function.

The data pipe is now sent into the return_molecule, return_residue, and return_spin function calls.

Fix for the convert_from_global_index() method.

An uninitialised variable is now set to 0.

Fix for the duplicate_data() method by calling the new convert_from_global_index() function.

Created the new function convert_from_global_index().

This converts the global index into the molecule, residue, and spin indecies.

Completed the conversion of the model-free duplicate_data() method to the new design.

A few fixes for the model-free duplicate() method.

Removed the creation of the model selection data pipe, as this is now automatic.

This commit follows r6625 where the same change was applied to the full_analysis.py sample script.

Rearranged the pipe switching before data duplication.

Changed the pipe switching behaviour of the model_selection function.

Rather than finishing on the original current data pipe, as the function creates a model selection
pipe then the function finishes by switching to that pipe.

Added some pipe switching to the model selection code.

The current pipe at the start is stored, and then restored at the end.