relax SVN archive

Fix for the test_count_no_spins unit test - a data pipe now exists.

Added a unit test for the proper operation of the molecule loop when no data pipe is present.

Added a unit test for the proper operation of the spin loop when no data pipe is present.

Fixes for the unit tests of the spin and molecule loops when no data is present.

Fixed the unit test of the residue loop with no data pipes present.

The unittest framework couldn't handle the generator function, so an intermediary function was
created!

Added a unit test for the proper operation of the residue loop when no data pipe is present.

Added the generic_fns.pipes.test() function to the molecule, residue, and spin loop functions.

Created the test() function for testing the existence of the current or given data pipe.

Added a unit test for the proper operation of the residue loop when no data is present.

Added a unit test for the proper operation of the molecule loop when no data is present.