relax SVN archive

Updated the specific function files 'jw_mapping.py', 'relax_fit.py', and 'noe.py' for Grace
plotting.

The functions 'return_conversion_factor', 'return_grace_string', and 'return_units' have all been
added to make these classes work with the Grace plotting function.

Addition of the specific function 'return_grace_string'.

The function has been added to the files 'model_free.py' and 'jw_mapping.py' in the 'specific_fns'
directory, and has been made accessible in the specific setup file. The purpose of the function is,
when supplied the data type, to return a string formatted in Grace's typesetting syntax. That way
parameter names can be displayed on the Grace axes as Greek text, superscript, subscript, italics,
or any other Grace format.

The file 'specific_fns/jw_mapping.py' has also had the 'return_data_name' function expanded to
include the spectral densities themselves.

Modified the appearance of the Grace plot.

The settings in the Grace header function have been tweaked.

Rename of the function 'get_data_name' to 'return_data_name'.

Modification of the Grace plotting functions such that minimisation statistics can now be plotted as
well. This includes plotting of statictics for Monte Carlo simulations. Two dummy functions
'return_conversion_factor' and 'return_units' were added to 'generic_fns/minimise.py' so that the
use of these does nothing to the statistics.

Addition of functions to return minimisation statistics. The two functions 'return_value' and
'get_data_name' have been added to 'generic_fns/minimise.py' to return the value of minimisation
statistics.

The function for resetting the minimisation statistics, 'reset_min_stats', has been moved from
'generic_fns/value.py' to 'generic_fns/minimise.py' and has been expanded for resetting global
statistics.

Modification of the Grace plots in that parameters are now plotted as their external representation
rather than the internal program representation. The writing function now calls the specific
function 'return_conversion_factor' to convert the values. Axis labels together with the parameter
units are now included in the Grace file.

Change of the method for converting between internal parameter representation and external
representation.

Two specific function types have been added. The function 'return_convesion_factor' takes the name
of the parameter as an argument and returns the factor of conversion between internal and external
representations. The function 'return_units' takes the name of the parameter as an argument and
returns a string representation of the units, for example 'Angstrom'.

The results reading and writing functions in 'specific_fns/model_free.py' were modified to use these
functions.

Rewrite of the Grace plotting functions.

The major rewrite involved the Grace file writing functions. XY plots of any combination of data
for the X-axis and Y-axis can now be created. Support for Monte Carlo simulation data has also been
added.

The prompt function 'grace.view' and generic function 'view' in 'generic_fns/grace.py' have been
changed such that they will now only execute Grace. Previously the functions were also able to
create a grace file.

The regular expression doc string which is displayed in both the 'grace' and 'value' class of
functions has been moved out into its own module called 'prompt/doc_string.py'. Previously the doc
string was duplicated in both classes, the change will prevent the strings from getting out of sync.

A new Exception class called RelaxNoSimError has been added for when simulations are required but do
not exist.

The function 'return_value' in 'specific_fns/model_free.py' has been modified to return simulation
values when asked.