relax SVN archive

The proper spin specific peak intensity errors are now input into the relax-fit minimise() method.

Fixed the setting of the spin specific peak intensity errors in __errors_repl().

This should be an array equal to cdp.sigma_I.

Some whitespace cleanups.

Replaced all references to 'average peak intensity'. These are no longer averaged.

Some fixes for the back_calc() relax-fit method.

Not sure if this method will work yet!

Removal of the mean_and_error() method. This is now part of generic_fns.spectrum.

Print out refinement of the __errors_repl() function.

The spin specific error structure intensity_err is now set for each selected spin.

A number of fixes for the __errors_repl() function.

The variance and sd structures are now correctly created, and the variances properly averaged.

Fix for the calculation of the average variance.