relax SVN archive

Expanded the Structure.test_pca system test checks to compare to the values from Gromacs.

Improved the graphs in the backend of the structure.pca user function.

The graphs are now clustered so that different models of the same structure in the same data pipe
are within one graph set. The graph header has also been improved.

Created an initial Structure.test_pca system test.

This executes the new structure.pca user function, and checks if data is stored in cdp.structure.

Updated the Gromacs PCA results for the newest Gromacs version (5.1.1).

Added the Gromacs PCA results for the distribution.pdb file.

This includes a script used to execute all parts of Gromacs and all output files.

The structure.pca user function now creates graphs of the PC projections.

This includes PC1 vs. PC2, PC2 vs. PC3, etc.

Modified the assemble_structural_coordinates() method to return more information.

This is from the pipe_control.structure.main module. The 'lists' boolean argument is now accepted
which will cause the function to additionally return the object ID list per molecule, the model
number list per molecule, and the molecule name list per molecule.

Added the 'format' and 'dir' arguments to the structure.pca user function.

This is to the front and back ends.

The PCA values and vectors, and the per structure projections are now being stored.

This is in the structure.pca user function backend in the pipe_control.structure.main module.

The PCA analysis function in the relax library is now returning data.

This includes the PCA values and vectors, and the per structure projections.