Scoring classes can now be imported directly from ost.mol.alg.

affects fnat/fnonnat/irmsd/dockq scores by
1) lowering distance threshold for two residues considered to be in contact
(5A -> 4A)
2) definition of interface residues. A residue is defined as interface
residue if any of its atoms is within 10A of another chain. CAPRI suggests
to lower the default to 8A in combination with only considering CB atoms
for protein peptide interactions.

This is similar to ilddt which is used as target metric in the new
AlphaFold3 paper

and some cleanup...

we differentiate between pair states, i.e. errors related to a specific
pair of model/target ligands, and single ligand states, i.e. errors
That affect one particular ligand. An error state in the latter basically
takes that ligand out of the race for assignment.

This is mainly for debug purposes

That was stupid before

Only initial work done for a base scoring class that takes care
of ligand prep, computing ligand symmetries and calling score computation
functionality from child classes. Child class for SCRMSD is already there
with basic testing.