relax SVN archive

A docstring and comment correction.

Implemented the generic_fns.spin.renumber() function.

Added a unit test for renumbering spins.

And another comment fix (fixing the last fix).

A comment fix.

Added checks to the spin renaming unit test to make sure other spins are not renamed.

Added a unit test for renaming many spins simultaneously.

Added a description of the data setup for all the spin unit tests.

Fixes for the spin renaming unit test.

Implemented the generic_fns.spin.rename() function.