relax SVN archive

Speed ups for the 'NS 2-site 3D' model.

The pi-pulse propagator is created only once upon target function initialisation rather than for
each function call, each spin cluster, each magnetic field strength, each dispersion point, and each
CPMG block.

Converted the pi-pulse propagator matrices to numpy array format.

This is to enable the use of the much faster numpy.dot() function for performing the dot products.

Improvements to the nesting() method of the relaxation dispersion auto-analysis.

The use of the parameters of the simpler model in a nested pair now only works if the simpler model
is in the model list.

Added the relax wiki backup script for dumping the MySQL database contents locally.

This is from http://article.gmane.org/gmane.science.nmr.relax.devel/4163.

Lots of fixes for the relaxation dispersion target function module for the 'NS 2-site 3D' model.

Added support for the 'NS 2-site 3D' model to the relax_disp.select_model user function back end.

This is the model of the numerical solution for the 2-site Bloch-McConnell equations. It originates
as optimization function number 1 from the fitting_main_kex.py script from Mathilde Lescanne, Paul
Schanda, and Dominique Marion (see http://thread.gmane.org/gmane.science.nmr.relax.devel/4138,
https://gna.org/task/?7712#comment2 and https://gna.org/support/download.php?file_id=18262).

This commit follows step 6 of the relaxation dispersion model addition tutorial
(http://thread.gmane.org/gmane.science.nmr.relax.devel/3907).

Converted the 'NS 2-site' model to 'NS 2-site 3D' to be more specific.

This might change again in the future.

Spacing fix in an import statement (found using the 2to3 conversion program).

Created the 'NS 2-site' model target function.

This is the model of the numerical solution for the 2-site Bloch-McConnell equations. It originates
as optimization function number 1 from the fitting_main_kex.py script from Mathilde Lescanne, Paul
Schanda, and Dominique Marion (see http://thread.gmane.org/gmane.science.nmr.relax.devel/4138,
https://gna.org/task/?7712#comment2 and https://gna.org/support/download.php?file_id=18262).

This commit follows step 4 of the relaxation dispersion model addition tutorial
(http://thread.gmane.org/gmane.science.nmr.relax.devel/3907).

Updates and fixes for the lib.dispersion.ns_2site module.

The function has been renamed, and the R1 arguments default to 0.0. The flip angle for the
r180x_3d() function has also been removed as the angle has been changed to include the 180 degrees
from the pulse.