Completed all of the heteronucl_T1 tags in the base class and v2.1 classes.
The saveframe name and label are now set in the v3.1 class.
All the heteronuclear T1 tags are now initialised.
Fix for the v3.0 relaxation class.
Clean up of the NMR-STAR python objects.
Import fix for the v2.1 relaxation module.
Fix for the v2.1 T1 tag category.
Split the v2.1 heteronucl_T1_relaxation saveframe into its own module.
Expanded the heteronuclear T1 v3.1 module to include all tag names.
The version string is now being printed, rather than recreating it.
