relax SVN archive

This bug was a result of modifications to the file 'specific_fns/relax_data.py' not being complete.

The function 'self.initialise_data' has been removed from 'specific_fns/base_class.py'.

The functions 'self.data_init' in the other three files were modified to incorporate the code no
longer in 'self.initialise_data'.

The function 'self.update_global_data_structures' was added to 'specific_fns/relax_data.py' and all
the functions which create global data structures now call it.