relax SVN archive

Started to redesign add_struct() to remove the struct_index arg and convert to the new model design.

The API base class function get_model() has been added to return or create the desired model. The
add_struct() method has been renamed to add_molecule(). Much work remains to be done.

Support for models vs. molecules and the elimination of struct_index in bond_vectors().

Fix for the struct_index arg unit test of structure.vectors().

The arg is now called 'model'.

Added a verbosity flag to parse_token() so that print outs are suppressed by default.

Docstring fixes for vectors().

Support for models vs. molecules and elimination of struct_index in vectors().

Modified the prompt interface of the structure.vectors() user function.

The struct_index arg is dead! Long live the model arg!

Corrected mistakes in English.

Corrected mistakes in English.

Corrected the way the scaling matrix is assembled.

This is as proposed by Ed in a post at:
https://mail.gna.org/public/relax-devel/2009-01/msg00079.html
(Message-id: <7f080ed10901130637k34ce0fc1l57091178e09940a8@...>)

The scaling values are now based on the default values for the different parameters which were
slightly modified.

The only parameter for which the average is still used (as for intensities in the 'relax_fit.py'
code) is 'R2eff'.