relax SVN archive

Big bug fix for the error_analysis.covariance_matrix user function.

The model_info structure is now being passed into the get_param_names() API method, as required by
the API.

Updated the relaxation curve-fitting get_param_names() API method to handle all models.

This now simply returns the spin container 'params' list, allowing all models to be properly
supported.

The errors in the Relax_fit.test_saturation_recovery system test are now reasonable.

They have been set to 5% of Iinf so that the chi-squared value during optimisation is more
realistic.

Updated the relaxation curve-fitting covariance_matrix() API method to handle all models.

The check for the 'exp' model type has been eliminated, and the parameter vector is assembled using
the flexible assemble_param_vector() function rather than manually constructing the vector.

Expanded the relax_fit_saturation_recovery.py system test script.

This now calls the error_analysis.covariance_matrix user function to test that code path.

Added support for the inversion recovery experiment to parameter disassembly function.

This matches the change of r26833 for the saturation recovery experiment. This is in the
disassemble_param_vector() function of the specific_analyses.relax_fit.parameters module. This
function requires each experiment to be handled separately.

The relax_fit.relax_time and relax_fit.select_model user functions now have wizard graphics.

The R1 graphic from graphics/analyses/r1_200x200.png is now being used.

Expansion and improvements for the relax_fit.select_model user function documentation and printouts.

Split the saturation recovery exponential equations and partial derivatives into their own C file.

Implemented the target functions for the saturation recovery exponential curve.

In the Python target function class Relax_fit_opt, the new func_sat(), dfunc_sat() and d2func_sat()
methods have been created as wrappers for the new C functions. These are aliased to func(), dfunc()
and d2func() in the __init__() method.

In the target_functions/exponential.c C file, the functions exponential_sat(),
exponential_sat_dIinf(), exponential_sat_dR(), exponential_sat_dIinf2(), exponential_sat_dR_dIinf()
and exponential_sat_dR2() have been created to implement the function, gradient, and Hessian for the
equation I = Iinf * (1 - exp(-R.t)).

In the target_functions/relax_fit.c file, the functions func_sat(), dfunc_sat(), d2func_sat(),
jacobian_sat() and jacobian_chi2_sat() have been created as duplications of the *_exp() functions,
but pointing to the exponential_sat*() functions and using Iinf instead of I0.