relax SVN archive

Added an NOE normalisation variable to the stereochem_analysis.py sample script.

Fix for the write_xy_header() function for when the data_type arg is not supplied.

The number of ensembles string is now more nicely formatted in the subtitle.

This is in Stereochem_analysis.grace_plots().

Stereochem_analysis.grace_plots() now uses the new write_xy_header() & write_xy_data() fns.

The line type for each set can now be specified in write_xy_header().

The linewidth for all graph elements can now be set in write_xy_header().

The symbol fill style can now be specified in write_xy_header().

The graph view port size can now be changes and defaults to a larger value.

The grace version of the write_xy_header() header is not output.

The 'Spin ' text is now prepended to the legend only in get_data(), and not write_xy_header().