relax SVN archive

Started to change the structure.vectors backend to handle two spin IDs.

Renamed return_spin_from_id() to return_spin(), and return_spin() to return_spin_from_selection().

This shaves off a number of seconds from the system test - the look up table speed ups will come
with support in the other mol_res_spin module functions.

return_spin_from_id() now defaults to return_spin() when the spin ID is not in the lookup table.

The slower return_spin() method will allow return_spin_from_id() to always be functional.

Added the 'pipe' argument to generic_fns.mol_res_spin.return_spin_from_id().

This is to mimic the return_spin() function.

Fix for the gui.misc.bitmap_setup() function for Mac OS X - all bitmaps with alpha had black backgrounds!

Fix for return_residue() for a bug introduced at r16910.

Created generic_fns.mol_res_spin.return_spin_from_id() for returning spin containers from spin IDs.

generic_fns.mol_res_spin.create_pseudo_spin() is now adding data to the spin ID look up table.

To support this, the return_residue() method now takes the 'indices' argument and returns the
molecule and residue indices.

Started to fill up the spin ID look up table.

The index_molecule() and index_residue() functions have been added to determine the MoleculeList and
ResidueList indices of given molecules and residues. These are used by the create_spin for
efficiency and to allow the indices (together with the spin index and spin ID string) to be
assembled into the look up table. This table is not used anywhere yet.

Initialised a look up table in the cdp.mol structure for faster spin access.

This look up table will be slowly transitioned to, and should significantly speed up certain
operations.