relax SVN archive

Many updates and improvements to the spin selection and deselection functions.

Added the boolean arg to the desel_spin() function.

Another fix for the sel_read() function.

Changed all selection flags to bools.

Fixes for the sel_read() function.

Fixed the sel_spin() function.

Fix for the select.spin() user function.

Fix for the system test of storing the S2 difference in a new data pipe.

Cut most of the residues from the relaxation curve fitting system test to speed things up.

Updated the set_error() method to the new design.