[IMP-dev] Refactored distance computations

[Daniel Russel <drussel@gmail.com>]

I pulled the basic distance pair score computation into an internal  
function defined DistancePairScore.h. This function takes an offset  
and a scale, so the SphereDistancePairScore, DistancePairScore and  
bond restraints can all use it internally.

Attachment: refactor_distance
Description: Binary data