relax SVN archive

Shifted calc_chi_tensor() and kappa() from pipe_control.align_tensor to lib.alignment.alignment_tensor.

The frame order analysis is now using the correct centre of mass function.

Speed ups for the interatom_loop() by restoring some of the code deleted at r19149.

This spin ID lookup table is being used again, as this is much faster than the string parsing of
spin IDs.

Restored the selection object __contains_spin_id() method as contains_spin_id().

This will allow for faster checks for matches to spin ID strings.

Fix for the pipe_control.relax_data.pack_data() function for the selection object changes.

Fixes for the cone PDB representation.

Fixes for the interatomic_loop() function for the selection object changes.

Removed the parser argument from structure.read_pdb in the stereochemistry auto-analysis.

More removals of the now dead parser argument for the structure.read_pdb user function.

Fix for the select.domain user function backend for the changes to the selection object.