relax SVN archive

Fix for the BMRB system test which was broken due to the restructuring of the sample_scripts directory.

Added a sample script for the unsuccessful two domain N-state model optimisation.

Added two sample scripts for determining the populations of an ensemble of small molecules.

This uses RDCs and PCSs with the N-state model to study the dynamics of small organic molecules.

Created a sample script subdirectory called n_state_model.

Deleted the incomplete and useless N_state_model.py sample script.

Added a sample script for creating plots of experimental verses back calculated relaxation data.

Updated the OpenDX mapping sample scripts from the relax 1.2 to the 1.3 design.

Updated all of the sample scripts for the new relaxation data ID string design.

Added copyright headers to all of the sample scripts, and updated the introduction text.

This allows users to determine the age of the scripts.

Updated the CV model-free model selection script to the new relax data ID string design.