Added system for using generic file for reading spins.

Work in progress for Support Request #3044, (https://gna.org/support/index.php?3044) - Load spins from SPARKY list.
Modified the generic list to also return spin information when intensity is not present.

Work in progress for Support Request #3044, (https://gna.org/support/index.php?3044) - Load spins from SPARKY list.
Added another systemtest for returning spins from a generic file.

Work in progress for Support Request #3044, (https://gna.org/support/index.php?3044) - Load spins from SPARKY list.
Fix for a script in the test suite shared data for the recent relaxation dispersion changes.