Add ability to have BD reject moves that cause collisions

[drussel]

• Use a Predicate to verify collisions so that RigidBodies can be used.
• maintain a ClosePairContainer and use something like Distribute to divide up list of particles so checking is efficient. @nkhuri

[drussel]

Add a list of predicates that must be satisfied to accept a move. We can then implement a SingletonPredicate that applies a PairPredicate to close pairs. Need to implement

• changes in BD
• expose a ScoreState that allows fetching of near neighbors of particles
• a few PairPredicates to check for collisions (RB based and single particle)
• a SingletonPredicate that implements the above.

[drussel]

A problem with that general approach is making sure that the ScoreState is updated properly. There are two aspects to this

• we don't want to have to update the NN list during the BD move, but we don't know how far things can move outside of it (although we can do it probabilistically)
• naively at least, nothing depends on the NN list during evaluate and so it won't necessarily get updated. Making optimizers and optimizer states ModelObjects might help with this.

[drussel]

Sometimes there are core dumps after running a while. /netapp/sali/nkhuri/HEMOGLOBIN/submit/new_run.sh