relax SVN archive

Started an implementation of Selection.__contains_spin_id().

Split up the Selection.__contains__() method to allow for string comparisons as well.

The MoleculeContainer, ResidueContainer, and/or SpinContainer comparison has been shifted to the
method Selection.__contains_mol_res_spin_containers().

Improved the test_Selection_full_spin_id() unit test to test all spins.

Removed the heteronuc arg test of the structure.vectors() user function.

This argument is no longer present.

Fixed all the unit tests of generic_fns.selection.generate_spin_id_data_array().

The function was recently renamed from generate_spin_id() to generate_spin_id_data_array().

Wrote the test_Selection_full_spin_id() for testing the string identifier '#Ap4Aase:2&:Glu@...&@NH'.

Added the start of the regular expression description in the id_string_doc string.

Fix for the atom_id string.

Started to write the new structural API method attached_atom().

Started to recode the vectors() function.

The structural API atom_loop() approach is completely wrong, so the spin_loop() will be used
instead.