Adapted NMR related data to new pdb format.

Adapted NMR related data to new pdb format.

Since gromacs had adopted the pdb output format to
some standard, the script to convert xplor files
with NMR restratints, such as can be downloaded from
the pdb do not work anymore. The script and accompanying
table have been updated to work with the new pdb format
and simultaneously the extra argument for a residue offset
has been removed. Now the script can be run like
xplor2gmx.pl conf.pdb < restraints.md > disre.itp

Change-Id: I7c3c8bd49b002e2bf0760f4226c913aa36d64611