relax SVN archive

Wrote the generic_fns.selection.tokenise() function and 28 unit tests covering the function!

The unit tests attempt to cover all proper and improper combinations of the selection string.

Small bug fix for the test_residue_loop_no_selection() unit test.

Implemented the generic_fns.selection.residue_loop() generator function.

Bug fix.

The spin_loop() and molecule_loop() generator functions now accept zero arguments for the selection
of everything. This fixes two of the unit tests. The test_molecule_loop_no_selection() unit test
has also been fixed.

Multiple unit tests for the spin_loop(), residue_loop(), and molecule_loop() generator functions.

These generator functions belong to the 'generic_fns.selection' module.

Created the RelaxMolSelectDisallowError and RelaxResSelectDisallowError errors.

Wrote the molecule_loop() generator function for looping over and returning molecule containers.

The full generator function is generic_fns.selection.molecule_loop().

Wrote the spin_loop() generator function for looping over and returning spin containers.

For more info, see my post at https://mail.gna.org/public/relax-devel/2006-10/msg00057.html
(Message-id: <1160557041.9523.74.camel@...>). The idea of the
generator function, using the yield statement, to return the spin data containers was given by Gary
Thompson at https://mail.gna.org/public/relax-devel/2007-01/msg00014.html (Message-id:
<f001463a0701071417w6bd7927cp8fdd052e698575ec@...>). More details are given by Chris
MacRaild at https://mail.gna.org/public/relax-devel/2007-01/msg00036.html (Message-ID:
<1168883717.7569.511.camel@...>).

The full generator function is generic_fns.selection.spin_loop().

Fixed the select.reverse() user function.

The generic_fns.selection.reverse() function still does not work as the spin_loop() function needs
to be implemented.

Bug fix. Removed the import of the now non-existant Selection class.