relax SVN archive

Modified all the relaxation dispersion test data Sparky files at 800 MHz.

The last three lines of the files were not properly formatted.

The relaxation dispersion target function class raises a RelaxError when the model is not implemented.

The relaxation dispersion target function class now imports the equations from lib.dispersion.equations.

Added the model argument to the dispersion target function class to select between different equations.

Fix for the Relax_disp.test_curve_fitting_cpmg_fast system test variable names.

The relaxation dispersion specific analysis code now uses the Python target function rather than the C.

Created a very basic initial target function class for relaxation dispersion.

This code is a translation of Sebastien Morin's C code in the old relax_disp branch. This old code
can be checked out with the commands:

$ svn co http://svn.gna.org/svn/relax/branches/relax_disp/maths_fns/relax_disp.c@r18123
$ svn co http://svn.gna.org/svn/relax/branches/relax_disp/maths_fns/relax_disp.h@r18123

Created the lib.dispersion.equations module.

This is a translation of Sebastien Morin's C code in the old relax_disp branch. The old C files can
be checked out with the command:

svn co http://svn.gna.org/svn/relax/branches/relax_disp/maths_fns/dispersion.c@r18123
svn co http://svn.gna.org/svn/relax/branches/relax_disp/maths_fns/dispersion.h@r18123

Updates for the relaxation dispersion system test scripts for the newer design of relax.

A number of changes were required as the code was quite old.

The cpmg_frq argument of the relax_disp.cpmg_frq user function can now be an integer as well as a float.