relax SVN archive

Turned off the optimisation constraints for the 'R2eff' model in the dispersion auto-analysis.

This follows from http://thread.gmane.org/gmane.science.nmr.relax.scm/22977/focus=6829.

This model does not require constraints at all, and the constraints only cause the optimisation to
take 10x longer to complete. Therefore the constraint flag has been set to False for the model.

Fixes for the new target_functions.relax_fit.jacobian() function.

The Python list of lists is now correctly created and returned.

Implementation of the target_functions.relax_fit.jacobian() function.

This follows from the discussions at http://thread.gmane.org/gmane.science.nmr.relax.devel/6807.

The function will calculate the Jacobian matrix for the exponential curve-fitting module. The
Jacobian can be used to directly calculate the covariance matrix, for example as described at
https://www.gnu.org/software/gsl/manual/html_node/Computing-the-covariance-matrix-of-best-fit-parameters.html.
The Jacobian is calculated using the help of the new exponential_dI() and exponential_dR() functions
in the target_functions/exponential.c file. These calculate the partial derivatives of the
exponential curve with respect to each model parameter separately.

The implementation still needs testing and debugging.

Removal of unnecessary imports in specific_analyses.relax_disp.optimisation().

task #7822(https://gna.org/task/index.php?7822): Implement user function to estimate R2eff and associated errors for exponential curve fitting.

Fix for missing imports.

task #7822(https://gna.org/task/index.php?7822): Implement user function to estimate R2eff and associated errors for exponential curve fitting.

Implemented first try to minimise with minfx in estimate_r2eff() function.

task #7822(https://gna.org/task/index.php?7822): Implement user function to estimate R2eff and associated errors for exponential curve fitting.

Split function to minimise with scipy.optimize.leastsq out in estimate_r2eff module.

This is to prepare for implementing with minfx.

Isolated all code related to user function:

relax_disp.r2eff_estimate() into independent module file.

All has been isolated to: specific_analyses.relax_disp.estimate_r2eff.

Moved target function for curve fitting with scipy into specific_analyses.relax_disp.estimate_r2eff.

This will later include the backend specific_analyses.relax_disp.optimisation.estimate_r2eff()
function and the code in the target_functions package.

The code in target_functions.relax_disp_curve_fit is a lot more than just a target function, so it doesn't really belong in this package.

This is also to isolate this experimental feature.

Re-used the dependency check "scipy_module", since leastsq() has been part of Scipy since 2003.